UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   FORM 10-QSB

             (X) QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
                  For the quarterly period ended March 31, 2005

                                       OR

              ( ) TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934
                    For the transition period from to________

Commission File Number 1-31398

                        NATURAL GAS SERVICES GROUP, INC.
        (Exact name of small business issuer as specified in its charter)

           Colorado                                             75-2811855
(State or other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                              Identification No.)

                                  2911 SCR 1260
                              Midland, Texas 79706
                    (Address of principal executive offices)

                                 (432) 563-3974
                (Issuer's telephone number, including area code)

                                       N/A
     ----------------------------------------------------------------------
              (Former name, former address and former fiscal year,
                          if changed since last report)


Check  whether the issuer (1) filed all reports  required to be filed by Section
13 or 15(d) of the  Exchange  Act during the past 12 months (or for such shorter
period that the registrant was required to file such reports),  and (2) has been
subject to such filing requirements for the past 90 days.

                                    Yes X  No 
                                       ---   ---

                      APPLICABLE ONLY TO CORPORATE ISSUERS

State the number of shares outstanding of each of the issuer's classes of common
equity, as of the latest practicable date.

                                                                Outstanding at
          Class                                                   May 16, 2005

Common Stock, $.01 par value                                        6,782,764

Transitional Small Business Disclosure Format (Check one):  Yes    No X    
                                                               ---   ---





NATURAL GAS SERVICES GROUP, INC.


Part I - FINANCIAL INFORMATION
------------------------------

Item 1.  Financial Statements

Unaudited Consolidated Balance Sheet......................................Page 1


Unaudited Consolidated Income Statements..................................Page 2


Unaudited Consolidated Statements of Cash Flows...........................Page 3


Notes to Unaudited Consolidated Financial Statements......................Page 4


Item 2.  Management's Discussion and Analysis or Plan of Operation........Page 7
-------  

Item 3.  Control and Procedures..........................................Page 10
-------

Part II - OTHER INFORMATION

Item 1.  Legal Proceedings...............................................Page 11
-------

Item 6.  Exhibits........................................................Page 11
-------

Signatures...............................................................Page 17





                        Natural Gas Services Group, Inc.
                      Condensed Consolidated Balance Sheet
                                   (unaudited)
                                 March 31, 2005

                                     ASSETS
Current Assets:
   Cash and cash equivalents                                         $ 1,370,843
   Accounts receivable - trade, net of allowance                       3,494,876
   Inventory                                                          10,620,317
   Prepaid expenses                                                      218,955
                                                                     -----------
              Total current assets                                    15,704,991
                                                                     
Lease equipment, net of accumulated depreciation                      31,150,928
Other property, plant and equipment, net of depreciation               6,421,495
Goodwill, net of accumulated amortization                              8,124,216
Intangible, net of accumulated amortization                            4,219,767
Restricted cash                                                        2,000,000
Other assets                                                             137,403
                                                                     -----------
             Total Assets                                            $67,758,800
                                                                     ===========
                                                                     
                      LIABILITIES AND SHAREHOLDERS' EQUITY           
                                                                     
Current Liabilities:                                                 
   Current portion of long term debt                                 $ 5,399,056
   Bank line of credit                                                    18,087
   Accounts payable and accrued liabilities                            5,429,194
   Unearned Income                                                       731,673
                                                                     -----------
         Total current liabilities                                    11,578,010
                                                                     
Long term debt, less current portion                                  18,998,407
Subordinated notes, net of discount                                    4,465,538
Deferred income tax payable                                            3,485,610
                                                                     -----------
              Total liabilities                                       38,527,565
                                                                     
Common Stock                                                              67,825
Paid in Capital                                                       21,778,261
Retained Earnings                                                      7,385,149
                                                                     -----------
               Shareholders' Equity                                   29,231,235
                                                                     -----------
              Total Liabilities and Shareholders' Equity             $67,758,800
                                                                     ===========
                                                             


See accompanying notes to these condensed consolidated financial statements.


                                                                               1


                        Natural Gas Services Group, Inc.
                    Condensed Consolidated Income Statements
                                   (unaudited)
                                                   Three months ended March 31, 
                                                       2005            2004
                                                   ------------    ------------
Revenue:                                           
   Sales                                           $  7,146,137    $    889,965
   Service and maintenance income                       463,781         423,602
   Leasing income                                     3,431,317       2,254,784
                                                   ------------    ------------
                                                     11,041,235       3,568,351
                                                   ------------    ------------
Cost of revenue:                                   
   Cost of sales                                      5,622,167         646,394
   Cost of service and maintenance                      290,099         336,250
   Cost of leasing                                    1,207,758         568,409
                                                   ------------    ------------
        Total cost of revenue                         7,120,024       1,551,053
                                                   ------------    ------------
Gross Margin                                          3,921,211       2,017,298
                                                   
 Operating Cost:                                   
   Selling expense                                      229,691         177,389
   General and administrative expense                   903,800         488,260
   Amortization & depreciation                          950,815         526,685
                                                   ------------    ------------
                                                      2,084,306       1,192,334
                                                   ------------    ------------
Operating income                                      1,836,905         824,964
                                                   
   Interest expense                                    (421,773)       (180,608)
   Other income                                          10,835       1,501,081
                                                   ------------    ------------
Income before income taxes                            1,425,967       2,145,437
     Income tax expense                                 527,607         251,698
                                                   ------------    ------------
Net income                                              898,360       1,893,739
   Preferred dividends                                     --            27,922
                                                   ------------    ------------
Net income available to common shareholders        $    898,360    $  1,865,817
                                                   ============    ============
                                                   
                                                   
         Earnings per share:                       
         Basic                                     $       0.13    $       0.37
         Diluted                                   $       0.11    $       0.36
         Weighted average Shares:                  
         Basic                                        6,728,095       5,065,327
         Diluted                                      7,827,206       5,221,441
                                                   
                                              
See accompanying notes to these condensed consolidated financial statements.


                                                                               2




                        Natural Gas Services Group, Inc.
                 Condensed Consolidated Statements of Cash Flows
                                   (unaudited)
                                                                               Three Months      Three Months
                                                                                  Ended             Ended
                                                                              March 31, 2005    March 31, 2004
                                                                              --------------    --------------
                                                                                                     
CASH FLOWS FROM OPERATING ACTIVITIES:                                                              
   Net Income                                                                 $      898,360    $    1,893,739
      Adjustments to reconcile net income to net cash provided by operating                        
       activities:                                                                                   
      Depreciation and amortization                                                  950,815           526,686
      Deferred taxes                                                                 527,610           251,698
      Amortization of debt issuance costs                                             16,239            16,239
      Gain on disposal of assets                                                     (45,846)             --
      Changes in current assets and liabilities:                                                   
      Trade and other receivables                                                  1,342,909        (1,732,493)
      Inventory and work in progress                                              (1,596,502)         (709,403)
      Prepaid expenses and other                                                     (30,672)          (53,012)
      Accounts payable and accrued liabilities                                       829,651         1,213,472
      Deferred income                                                               (226,640)         (204,104)
      Other assets                                                                   297,858             3,273
                                                                              --------------    --------------
  NET CASH PROVIDED BY OPERATING ACTIVITIES                                        2,963,782         1,206,095
                                                                              --------------    --------------
                                                                                                   
CASH FLOWS FROM INVESTING ACTIVITIES:                                                              
    Purchase of property and equipment                                            (4,667,716)       (2,530,447)
    Assets acquired, net of cash                                                  (7,553,965)             --
    Proceeds from sale of property and equipment                                     180,166              --
                                                                              --------------    --------------
  NET CASH USED IN INVESTING ACTIVITIES                                          (12,041,515)       (2,530,447)
                                                                              --------------    --------------
                                                                                                   
CASH FLOWS FROM FINANCING ACTIVITIES:                                                              
   Net proceeds from bank loans                                                   13,469,113         1,952,778
   Repayments of long term debt                                                   (4,014,839)         (604,143)
   Dividends paid on preferred stock                                                    --             (27,922)
   Proceeds from exercise of warrants and stock options                              309,115            23,575
                                                                              --------------    --------------
NET CASH PROVIDED BY FINANCING ACTIVITIES                                          9,763,389         1,344,288
                                                                              --------------    --------------
NET INCREASE IN CASH                                                                 685,656            19,936
CASH AT BEGINNING OF PERIOD                                                          685,187           176,202
                                                                              --------------    --------------
CASH AT END OF PERIOD                                                         $    1,370,843    $      196,138
                                                                              ==============    ==============
                                                                                                   
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:                                                  
      Interest paid                                                           $      378,027    $      180,608
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:                            
     Assets acquired for issuance of subordinated debt                        $    3,000,000       
                                                                              ==============       
     Assets acquired for issuance of common stock                             $    5,120,438       
                                                                              ==============       

                                                                                

See accompanying notes to these condensed consolidated financial statements.

                                                                               3




                     NOTES TO CONDENSED FINANCIAL STATEMENTS

(1) Basis of Presentation

         The   accompanying   unaudited   financial   statements   present   the
consolidated  results of our company  taken from our books and  records.  In our
opinion,  such information  includes all adjustments,  consisting of only normal
recurring  adjustments,  which are necessary to make our  financial  position at
March 31, 2005 and the  results of our  operations  for the three  month  period
ended  March 31, 2005 and 2004 not  misleading.  As  permitted  by the rules and
regulations  of the Securities and Exchange  Commission  (SEC) the  accompanying
financial  statements  do not  include  all  disclosures  normally  required  by
accounting principles generally accepted in the United States of America.  These
financial statements should be read in conjunction with the financial statements
included  in our Annual  Report on Form 10-KSB for the year ended  December  31,
2004 on file with the SEC. In our opinion, the consolidated financial statements
are a fair  presentation  of the financial  position,  results of operations and
cash flows for the periods presented.

         The results of  operations  for the three month  period ended March 31,
2005 are not necessarily  indicative of the results of operations to be expected
for the full fiscal year ending December 31, 2005.

(2) Stock-based Compensation

         Statement   of   Financial   Accounting   Standards   No.   123  ("SFAS
123"),"Accounting  for  Stock-Based  Compensation,"  encourages,  but  does  not
require,  the adoption of a fair  value-based  method of accounting for employee
stock-based  compensation  transactions.  However  we have  elected to apply the
provisions  of  Accounting  Principles  Board  Opinion  No. 25  ("Opinion  25"),
"Accounting  for Stock Issued to  Employees,"  and related  interpretations,  in
accounting for our employee  stock-based  compensation  plans. Under Opinion 25,
compensation  cost is measured as the excess, if any, of the quoted market price
of our stock at the date of the grant above the amount an  employee  must pay to
acquire the stock.

         Had  compensation  costs for  options  granted  to our  employees  been
determined based on the fair value at the grant dates consistent with the method
prescribed  by SFAS No. 123,  our net income and  earnings  per share would have
been reduced to the pro forma amounts listed below:

                                                                          Three Months Ended
                                                                              March 31,
                                                                         2005            2004
                                                                     -----------     -------------
                                                                                         
Pro forma impact of fair value method

   Net income available to common shareholders, as reported          $   898,360     $   1,865,817
   Pro-forma stock-based compensation costs under the fair
   value method, net of related tax                                      (46,000)          (10,000)
                                                                     -----------     -------------
   Pro-forma income applicable to common shares under the
   fair-value method                                                 $   852,360     $   1,855,817
   Earnings per common share
   Basic earnings per share reported                                        0.13              0.37
   Diluted earnings per share reported                                      0.11              0.36
   Pro-forma basic earnings per share under the fair value method           0.13              0.37
   Pro-forma diluted earnings per share under the fair value method         0.11              0.36



                                                                               4


Weighted average Black-Scholes fair value assumptions:
   Risk free rate                                                      4.0%-6.8%         4.0%-5.2%
   Expected life                                                        0-10 yrs          5-10 yrs
   Expected volatility                                                     39.0%             44.0%
   Expected dividend yield                                                  0.0%              0.0%


 (3) Acquisition

         On October 18, 2004, we entered into a Stock  Purchase  Agreement  with
Screw  Compression  Systems,  Inc., or "SCS", and the stockholders of SCS. Under
this agreement,  we agreed to purchase all of the outstanding  shares of capital
stock of SCS for the purpose of expanding our product line,  production capacity
and customer base.

         SCS is a manufacturer  of natural gas  compressors,  with its principal
offices located in Tulsa, Oklahoma.

         The  stockholders of SCS received,  in  proportionate  shares (based on
their stock ownership of SCS), a total of $16.1 million.

         o        $8 million in cash;
         o        promissory  notes  issued  by  Natural  Gas  Services  in  the
                  aggregate  principal  amount of $3 million bearing interest at
                  the rate of 4.00% per  annum,  maturing  three  years from the
                  date of closing  and secured by a letter of credit in the face
                  amount of $2 million; and
          o       609,576 shares of Natural Gas Services  common stock valued at
                  $5.1 million.  All of the shares are  "restricted"  securities
                  within  the  meaning of Rule 144 under the  Securities  Act of
                  1933, as amended, and bear a legend to that effect.

         This  transaction was completed  January 3, 2005 and we began reporting
combined  financial  results for the first quarter 2005 included in this report.
The  total  purchase  price  was  $16.1  million  and we  recorded  goodwill  of
$4,984,561 and intangibles assets of $4,218,000.

         The following table  represents the combined results of operations on a
proforma  basis with Natural Gas Services  Inc. and Screw  Compression  Systems,
Inc. as if the acquisition had occured on January 1, 2004.

                                   (Unaudited)
                                Pro Forma Results
                        Three Months Ended March 31, 2004
   Revenue                                                      $8,900,478
   Net income                                                   $2,303,348
   Net Income per share, basic                                       $0.41
   Net income per share, diluted                                     $0.40

        
(4) Long Term Debt

         On Jan 3, 2005 we amended our  existing  loan  agreement  with  Western
Natural Bank to provide  additional  borrowings  for the cash portion of the SCS
acquisition  of $8 million for 84 months and interest of 1% over the prime rate.
This funding was  provided by entering  into a Third  Amended and Restated  Loan
Agreement made and entered into by and among Natural Gas Services  Group,  Inc.,
and Screw Compression Systems, Inc., and Western National Bank.



                                                                               5


         On March 14, 2005 we amended our existing loan  agreement  with Western
Natural Bank to provide  additional  borrowings of $10 million for 60 months and
interest of 1% over the prime rate.  This  funding will be used to invest in the
growth of our rental  fleet for the current  year.  This funding was provided by
entering into a Fourth Amended and Restated Loan Agreement made and entered into
by and among Natural Gas Services Group,  Inc., and Screw  Compression  Systems,
Inc., and Western National Bank.

         On May 1, 2005 we modified our  existing  loan  agreement  with Western
National  Bank to reduce the  current  interest  rate from 1% over prime to .50%
over prime and changed the current ratio  calculation  from 1.5 to 1.4 and this
modification  also allowed us to add the $2 million  restricted cash item on our
balance sheet to our current assets for calculating the bank covenants.

(5) Earnings per common share

         The following table  reconciles the numerators and  denominators of the
basic and diluted earnings per share computation.

                                                         Three Months Ended     
                                                               March 31,
                                                      -------------------------
                                                         2005          2004
                                                      -----------   -----------
Basic earnings per share                              
   Numerator:                                         
     Net income                                       $   898,360   $ 1,893,739
     Less: dividends on preferred shares                     --         (27,922)
                                                      -----------   -----------
     Net income available to common shareholders      $   898,360   $ 1,865,817
                                                      ===========   ===========
   Denominator -                                      
     Weighted average common shares outstanding         6,728,095     5,065,327
                                                      ===========   ===========
        Basic earnings per share                      $      0.13   $      0.37
                                                      ===========   ===========
Diluted earnings per share Numerator:                 
     Net income                                       $   898,360   $ 1,893,739
     Less: dividends on preferred shares (1)                 --         (27,922)
                                                      -----------   -----------
     Net income available to common shareholders      $   898,360   $ 1,865,817
                                                      ===========   ===========
   Denominator :                                      
     Weighted average common shares outstanding         6,728,095     5,065,327
      Dilutive effect of common stock options         
      and warrants                                      1,099,111       156,114
     Conversion of preferred shares (1)                      --            --
                                                      -----------   -----------
                                                        7,827,206     5,221,441
                                                      ===========   ===========
        Diluted earnings per share                    $      0.11   $      0.36
                                                      ===========   ===========
                                                   
(1) Preferred shares were anti-dilutive for the three months ended March 31,
2004.

(6) Segment information

FAS  No.  131,   Disclosures   About  Segments  of  an  Enterprise  and  Related
Information,   establishes  standards  for  public  companies  relating  to  the
reporting  of  financial  and  descriptive  information  about  their  operating
segments in  financial  statements.  Operating  segments  are  components  of an



                                                                               6




enterprise  about which  separate  financial  information  is available  that is
evaluated  regularly  by chief  operating  decision  makers in  deciding  how to
allocate resources and in assessing performance.

The Company identifies its segments based upon major revenue sources as follows:


For the three months ended March 31,2005               (in thousands of dollars)

                                             Service &
                                 Sales      Maintenance     Leasing      Corporate        Total
                              --------------------------------------------------------------------
                                                                        
Revenue                       $     7,146   $       464   $     3,431          --      $    11,041
Cost of Sales                       5,622           290         1,208          --            7,120
                              --------------------------------------------------------------------
Gross Margin                  $     1,524   $       174   $     2,223          --      $     3,921
Operating Expenses                   --            --            --           2,084          2,084
Other Income/(Expense)               --            --            --            (411)          (411)
                              --------------------------------------------------------------------
Income before Provision for                                                                
Income Taxes                  $     1,524   $       174   $     2,223   $    (2,495)   $     1,426
                              ====================================================================
*Segment Assets                      --            --            --     $    67,759    $    67,759
                              ====================================================================
                                                                                        

For the three months ended March 31, 2004              (in thousands of dollars)

                                             Service &
                                 Sales      Maintenance     Leasing      Corporate        Total
                              --------------------------------------------------------------------
Revenue                       $       890   $       424   $     2,254          --      $     3,568
Cost of Sales                         647           336           568          --            1,551
                              --------------------------------------------------------------------
Gross Margin                  $       243   $        88   $     1,686          --      $     2,017
Operating Expenses                   --            --            --           1,192          1,192
Other Income/(Expense)               --            --            --           1,320          1,320
                              --------------------------------------------------------------------
Income before Provision for                                                                 
Income Taxes                  $       243   $        88   $     1,686   $       128    $     2,145
                              ====================================================================
*Segment Assets                      --            --            --     $    32,786    $    32,786
                              ====================================================================

                                                                

     * Management does not track assets by segment.

Item 2.  Management's Discussion and Analysis, or Plan of Operation

Overview

         Our company provides  products and services to the oil and gas industry
and is engaged in (1) the manufacture,  service, sale, and rental of natural gas
compressors  to  enhance  the  productivity  of oil and gas  wells,  and (2) the
manufacture,  sale and rental of flares and flare ignition systems for plant and
production facilities.



                                       7


Critical Accounting Policies and New Accounting Pronouncements

         See our  December  31,  2004  Form  10-KSB  on file  with the SEC for a
discussion   of  our   critical   accounting   policies   and   new   accounting
pronouncements. There have been no substantive changes since that time.

Liquidity and Capital Resources

         We have funded our operations  through public and private  offerings of
our common and preferred stock,  subordinated  debt,  regular bank debt and cash
flow.  Proceeds were primarily used to pay debt and to fund the  manufacture and
fabrication of additional units for our rental fleet of natural gas compressors.

         At March 31, 2005, we had cash and cash  equivalents  of  approximately
$1,371,000,  working capital of $4,127,000 and bank debt of $24,400,000 of which
approximately  $5,399,000  was  classified as current.  We had positive net cash
flow from  operating  activities of  approximately  $2,964,000  during the first
three  months of 2005.  This was  primarily  from net  income of  $898,000  plus
depreciation  and  amortization  of $951,000  an  increase in deferred  taxes of
$528,000, an increase in accounts payable and accrued liabilities of $830,000, a
decrease in accounts  receivable-trade  of $1,343,000,  and an increase in other
asset of $299,000,  offset by an increase in deferred income of $226,000, and an
increase in inventory of $1,597,000.

         For the three months ended March 31,  2005,  we invested  approximately
$4,668,000  in  equipment  for our  rental  fleet and in  service  vehicles.  We
financed  this  activity  with bank  debt of  approximately  $3,685,000  and the
remainder from operations.

         On January 3, 2005,  Natural Gas Services  Group,  Inc.  finalized  and
funded the Stock Purchase Agreement,  with Screw Compression  Systems,  Inc., or
"SCS",  and  the  stockholders  of SCS,  dated  October  18,  2004.  Under  this
agreement, Natural Gas Services Group purchased all of the outstanding shares of
capital stock of SCS.

         SCS manufacturers natural gas compressors,  and maintains its principal
offices located in Tulsa, Oklahoma.

         The  stockholders of SCS received,  in  proportionate  shares (based on
their stock ownership of SCS), a total of $16.1 million, consisting of:
         o        $8 million in cash;
         o        promissory  notes  issued  by  Natural  Gas  Services  in  the
                  aggregate principal amount of $3 million,  bearing interest at
                  the rate of four  percent  (4.00%) per annum,  maturing  three
                  years  from the date of  closing  and  secured  by a letter of
                  credit in the face amount of $2 million; and
         o        609,576 shares of Natural Gas Services  common stock valued at
                  $5.1 million, based on the average of the daily closing prices
                  of the common  stock for the ninety  consecutive  trading days
                  ended  April  28,   2004.   All  of  the  shares   issued  are
                  "restricted"  securities  within the meaning of Rule 144 under
                  the Securities  Act of 1933, as amended,  and bear a legend to
                  that effect.

         On March 14, 2005 we amended our existing loan  agreement  with Western
Natural Bank to provide  additional  borrowings of $10 million for 60 months and
interest of 1.0% over the prime rate. This funding will be used to invest in the
growth of our rental  fleet for the current  year.  This funding was provided by
entering into a Fourth Amended and Restated Loan Agreement made and entered into
by and among Natural Gas Services Group,  Inc., and Screw  Compression  Systems,
Inc., and Western National Bank.



                                       8


Results of Operations

Three months ended March 31, 2005,  Compared to the Three months ended March 31,
2004.

         Total revenue  increased from $3,568,000 to $11,041,000 or 209% for the
three  months  ended March 31, 2005  compared to the same period ended March 31,
2004. This was mainly the result of increased leasing income and the addition of
revenue from the acquisition of SCS.

         Sales  revenue  from  outside   sources   increased  from  $890,000  to
$7,146,000,  or 703% for the three months  ended March 31, 2005  compared to the
same period  ended March 31,  2004.  Sales from outside  sources  included:  (1)
Compressor  unit sales,  (2) Flare  sales,  (3) Parts  sales and (4)  Compressor
rebuilds. This increase was mainly the result of the sale of compressor units to
outside  third  parties by SCS in the three months ended March 31, 2005 compared
to the same period in 2004. SCS's outside sales were $6,756,000 for three months
ended March 31, 2005.

         Service and maintenance revenue increased from $424,000 to $464,000, or
9% for the three months  ended March 31, 2005  compared to the same period ended
March 31, 2004.

         Leasing revenue increased from $2,255,000 to $3,431,000, or 52% for the
three  months  ended March 31, 2005  compared to the same period ended March 31,
2004. This increase was the result of additional units added to our rental fleet
and leased to third  parties.  The company ended the period with 661  compressor
packages in its rental  fleet,  up from 585 units at  December  31, 2004 and 444
units at March 31, 2004.

       -------------------------------------------------------------------
       Total Revenue Percentage Breakdown for Three months ended March 31,
                                      2005
       -------------------------------------------------------------------
       Sales Revenue                                         65%
       ----------------------------------- ------ ------------------------
       Service & Maintenance Revenue                          4%
       ----------------------------------- ------ ------------------------
       Leasing Revenue                                       31%
       ----------------------------------- ------ ------------------------

         The gross  margin  percentage  decreased  from 57% for the three months
ended March 31,  2004,  to 36% for the same period  ended March 31,  2005.  This
decrease  resulted mainly from the relative increase in compressor sales revenue
as a percentage  of the total  revenue.  Our rental fleet carries a gross margin
averaging  65%, and  compressor  sales  margins  average 21% therefore the total
margins decrease as the lower margin product sales increase.

         Selling,  general and administrative expense increased from $666,000 to
$1,133,000  or 70% for the three months ended March 31, 2005, as compared to the
same period  ended March 31, 2004.  This was mainly the result of the  increased
expenses   attributed  to  the  SCS  acquisition.   The  selling,   general  and
administrative expenses for SCS for the quarter amount to 70% of the increase.

         Depreciation  and amortization  expense  increased 81% from $527,000 to
$951,000 for the three months ended March 31, 2005,  compared to the same period
ended March 31, 2004.  This  increase  was the result of 217 new gas  compressor
rental  units being added to rental  equipment  from March 31, 2004 to March 31,
2005.



                                       9


         Other income and expense  decreased  approximately  $1,490,000  for the
three months  ended March 31, 2005,  compared to the same period ended March 31,
2004.  This  decrease  was due  mainly  to the  receipt  of  $1,500,000  in life
insurance  payable upon the death of Mr. Wayne L. Vinson,  our former  President
and C.E.O in early  2004.  His death on March 15,  2004 left the  company as the
beneficiary  of two life insurance  policies,  one for  $1,000,000,  and one for
$500,000.

         Interest  expense  increased  134% for the three months ended March 31,
2005  compared to the same period ended March 31, 2004,  mainly due to increased
loan balances financing rental equipment and the loan for acquisition of SCS.

         Provision for income tax increased  $276,000 or 110%,  because  taxable
income increased after giving effect to the non taxable life insurance  proceeds
received in 2004. 

Forward Looking Statements

         Some   statements   contained  in  this  Report,   and  the   documents
incorporated by reference,  are "forward-looking  statements" within the meaning
of Section 27A of the Securities Act of 1933 (or Securities Act) and Section 21E
of the Exchange Act. These statements include,  without  limitation,  statements
relating  to oil and gas  prices,  demand  for oil and  gas,  budgets,  business
strategies  and other plans,  intentions  and  objectives of our  management for
future  operations and activities and other such matters.  The words  "believe",
"budget", "plan", "estimate", "expect", "intend", "strategy", "project", "will",
"could",  "may",  "anticipate",  "continue",  and similar  expressions  identify
forward-looking   statements.   We  believe  the  assumptions  and  expectations
reflected in these forward-looking statements are reasonable. However, we cannot
give any  assurance  that our  expectations  will prove to be correct or that we
will be able to take any actions  that are  presently  planned.  Actual  results
could differ materially from those expressed in the forward-looking  statements.
Factors that could cause such a difference include:

         o        fluctuations in prices of oil and gas;
         o        future capital requirements and availability of financing;
         o        competition;
         o        general economic conditions;
         o        governmental regulations;
         o        receipt of amounts owed to us by our customers;
         o        events similar to 9/11; and
         o        fluctuations in interest rates and availability of capital.
       
         You  are  cautioned  not  to  place  undue   reliance  on  any  of  our
forward-looking  statements,  which speak only as of the date of the document or
in the case of documents incorporated by reference, the date of those documents.

Item 3.  Controls and Procedures

(a) Evaluation of disclosure controls and procedures.

         Under the  supervision  and with the  participation  of our management,
including our chief executive officer and chief financial officer,  we evaluated
the  effectiveness  of the design and operation of our  disclosure  controls and
procedures  (as defined in Rule 13a-15(e)  under the Securities  Exchange Act of


                                                                              10


1934) as of the end of the  period  covered  by this  report.  Based  upon  that
evaluation,  our chief executive  officer and chief financial  officer concluded
that,  as of the end of the  period  covered  by  this  report,  our  disclosure
controls and procedures were effective with respect to timely  communicating  to
them and other members of management  responsible for preparing periodic reports
all material  information  required to be disclosed in our periodic filings with
the SEC.

(b) Changes in internal controls.

         There  were no  changes  in our  internal  controls  during  the period
covered by this report that have materially affected or are reasonably likely to
materially affect our internal controls over financial  reporting.  In addition,
to our knowledge there were no changes in other factors that could significantly
affect these controls subsequent to the date of their evaluation.






















                                                                              11


                           PART II - OTHER INFORMATION



NATURAL GAS SERVICES GROUP, INC.

Item 1.  Legal Proceedings

         From  time to  time,  we are a party  to  ordinary  routine  litigation
incidental  to our  business.  We are  not  currently  a  party  to any  pending
litigation,  and we are not aware of any threatened  litigation,  except for one
claim made by Karifico  Consultants in connection  with our acquisition of Screw
Compression Systems,  Inc. As we have previously reported,  Karifico Consultants
has advised us that a finder's fee in the amount of $300,000 is owed to Karifico
under terms of an  agreement  dated  November 3, 2003  between  Karifico and us.
However,  in reliance on a  subsequent  verbal  amendment of the  agreement,  we
tendered  payment in the amount of $150,000 in full  satisfaction  of Karifico's
claim under the November 3, 2003  agreement.  Karifico  disputes that its claims
have been fully satisfied.

Item 6.  Exhibits

         The following  exhibits are filed  herewith or  incorporated  herein by
reference, as indicated:

Exhibit No.                                Description
-----------                                -----------


   2.1            Purchase and Sale Agreement by and between Hy-Bon  Engineering
                  Company, Inc. and NGE Leasing, Inc. (Incorporated by reference
                  to Exhibit 2.1 of the Registrant's  Current Report on Form 8-K
                  dated  February  28,  2003 and filed with the  Securities  and
                  Exchange Commission on March 6, 2003)
   
   3.1            Articles  of  Incorporation,   as  amended   (Incorporated  by
                  reference to Exhibit 3.1 of the 10QSB filed and dated November
                  10, 2004)
   
   3.2            Bylaws  (Incorporated  by  reference  to  Exhibit  3.4  of the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   4.1            Form of warrant  certificate  (Incorporated  by  reference  to
                  Exhibit 4.1 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.2            Form of warrant agent agreement  (Incorporated by reference to
                  Exhibit 4.2 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.3            Form  of  lock-up  agreement  (Incorporated  by  reference  to
                  Exhibit 4.3 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.4            Form of  representative's  option for the  purchase  of common
                  stock  (Incorporated  by  reference  to  Exhibit  4.4  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   


                                                                              12


   4.5            Form of  representative's  option for the purchase of warrants
                  (Incorporated  by reference to Exhibit 4.5 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   4.6            Stockholders  Agreement,  dated  January 3, 2005 among Paul D.
                  Hensley,  Tony Vohjesus,  Jim Hazlett and Natural Gas Services
                  Group,  Inc.  (Incorporated by reference to Exhibit 4.3 of the
                  Registrant's From 8-K Report,  dated January 3, 2005, as filed
                  with the  Securities  and  Exchange  Commission  on January 7,
                  2005)   
                                                                        
                  Executive  Compensation Plans and Arrangements (Exhibits 10.1,
                  10.24, 10.25 and 10.26)
   
   10.1           1998 Stock Option Plan  (Incorporated  by reference to Exhibit
                  10.1 of the Registrant's  Registration Statement on Form SB-2,
                  No. 333-88314)
   
   10.2           Asset Purchase  Agreement,  dated January 1, 2001, between the
                  Registrant and Great Lakes Compression,  Inc. (Incorporated by
                  reference  to Exhibit  10.2 of the  Registrant's  Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.3           Exhibits  3(c)(1),  3(c)(2),   3(c)(3),   3(c)(4),   13(d)(1),
                  13(d)(2)  and  13(d)(3)  to Asset  Purchase  Agreement,  dated
                  January  1,  2001,  between  the  Registrant  and Great  Lakes
                  Compression,  Inc. (Incorporated by reference to Exhibit 10.14
                  of the Registrant's  Registration  Statement on Form SB-2, No.
                  333-88314)
   
   10.4           Amendment to Guaranty  Agreement  between Natural Gas Services
                  Group, Inc. and Dominion Michigan  Production  Services,  Inc.
                  (Incorporated by reference to Exhibit 10.3 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.5           Form of Series A 10% Subordinated  Notes due December 31, 2006
                  (Incorporated by reference to Exhibit 10.8 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.6           Form  of   Five-Year   Warrants  to  Purchase   Common   Stock
                  (Incorporated by reference to Exhibit 10.9 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.7           Warrants issued to Berry-Shino Securities,  Inc. (Incorporated
                  by reference to Exhibit 10.10 of the Registrant's Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.8           Warrants   issued   to   Neidiger,    Tucker,   Bruner,   Inc.
                  (Incorporated   by   reference   to   Exhibit   10.11  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   10.9           Form of  warrant  issued in March 2001 for  guaranteeing  debt
                  (Incorporated   by   reference   to   Exhibit   10.12  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   


                                                                              13


   10.10          Form of  warrant  issued in April 2002 for  guaranteeing  debt
                  (Incorporated   by   reference   to   Exhibit   10.13  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   10.11          Articles of Organization of Hy-Bon Rotary Compression, L.L.C.,
                  dated April 17, 2000  (Incorporated  by  reference  to Exhibit
                  10.18 of the Registrant's Registration Statement on Form SB-2,
                  No. 333-88314)
   
   10.12          Regulations of Hy-Bon Rotary Compression, L.L.C. (Incorporated
                  by reference to Exhibit 10.19 of the Registrant's Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.13          First  Amended  and  Restated  Loan   Agreement   between  the
                  Registrant  and  Western   National  Bank   (Incorporated   by
                  reference to Exhibit 10.1 of the  Registrant's  Current Report
                  on  Form  8-K,  dated  March  27,  2003  and  filed  with  the
                  Securities and Exchange Commission on April 14, 2003)
   
   10.14          Form of Termination of Employment Agreement Letter relating to
                  the  Employment  Agreement  of  Alan  Kurus  (Incorporated  by
                  reference to Exhibit 10.25 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   
   10.15          Form of Termination of Employment Agreement Letter relating to
                  the  Employment  Agreement  of Wayne Vinson  (Incorporated  by
                  reference to Exhibit 10.26 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   
   10.16          Form of Termination of Employment Agreement Letter relating to
                  the  Employment   Agreement  of  Earl  Wait  (Incorporated  by
                  reference to Exhibit 10.27 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   
   10.17          Triple Net Lease  Agreement,  dated June 1, 2003,  between NGE
                  Leasing, Inc. and Steven J. & Katherina L. Winer (Incorporated
                  by  reference  to  Exhibit  10.17 of the  Registrant's  Annual
                  Report on Form 10-KSB for the fiscal year ended  December  31,
                  2003)
   
   10.18          Lease  Agreement,  dated June 19,  2003,  between NGE Leasing,
                  Inc. and Wise Commercial Properties (Incorporated by reference
                  to Exhibit  10.18 of the  Registrant's  Annual  Report on Form
                  10-KSB for the fiscal year ended December 31, 2003)
   
   10.19          Lease Agreement,  dated March 1, 2004,  between the Registrant
                  and the City of Midland,  Texas  (Incorporated by reference to
                  Exhibit 10.19 of the  Registrant's  Form 10-QSB for the fiscal
                  quarter ended June 30, 2004)
   
   10.20          Second Amended and Restated Loan Agreement,  dated November 3,
                  2003,   between  the  Registrant  and  Western  National  Bank
                  (Incorporated   by   reference   to   Exhibit   10.20  of  the
                  Registrant's Form 10-QSB for the fiscal quarter ended June 30,
                  2004)
   


                                                                              14


   10.21          Securities  Purchase  Agreement,  dated July 20, 2004, between
                  the Registrant and CBarney Investments,  Ltd. (Incorporated by
                  reference to Exhibit 4.1 of the Registrant's Current Report on
                  Form 8-K dated July 20, 2004 and filed with the Securities and
                  Exchange Commission on July 27, 2004)
   
   10.22          Stock Purchase Agreement, dated October 18, 2004, by and among
                  the  Registrant,  Screw  Compression  Systems,  Inc.,  Paul D.
                  Hensley,  Jim  Hazlett  and  Tony  Vohjesus  (Incorporated  by
                  reference to Exhibit 4.1 of the Registrant's Current Report on
                  Form 8-K dated October 18, 2004 and filed with the  Securities
                  and Exchange Commission on October 21, 2004)
   
   10.23          Fourth  Amended and Restated Loan Agreement  (Incorporated  by
                  reference to Exhibit 10.1 of the  Registrant's  Current Report
                  on Form 8-K, dated March 14, 2005 as filed with the Securities
                  and Exchange Commission on March 18, 2005)
   
   10.24          Employment  Agreement  between Paul D. Hensley and Natural Gas
                  Services  Group,  Inc.  (Incorporated  by reference to Exhibit
                  10.1 of the  Registrants  Form 8-K  Report,  dated  January 3,
                  2005, as filed with the Securities and Exchange  Commission on
                  January 7, 2005)
   
   10.25          Employment Agreement between William R. Larkin and Natural Gas
                  Services  Group,  Inc.  (Incorporated  by reference to Exhibit
                  10.25 of the  Registrant's  Form  10-KSB for the  fiscal  year
                  ended  December 31, 2004,  and filed with the  Securities  and
                  Exchange Commission on March 30, 2005)
   
   10.26          Promissory  Note,  dated  January  3,  2005,  in the  original
                  principal amount of $2,100,000.00 made by Natural Gas Services
                  Group,  Inc.  payable  to Paul  D.  Hensley  (Incorporated  by
                  reference to Exhibit 10.26 of the Registrant's Form 10-KSB for
                  the fiscal year ended  December 31,  2004,  and filed with the
                  Securities and Exchange Commission on March 30, 2005)
   
   10.27          Third Amended and Restated Loan Agreement, dated as of January
                  3,  2005,  among  Natural  Gas  Services  Group,  Inc.,  Screw
                  Compression   Systems,   Inc.   and  Western   National   Bank
                  (Incorporated by reference to Exhibit 10.1 of the Registrant's
                  current  Report on form 8-K,  dated January 3, 2005, and filed
                  with the  Securities  and  Exchange  Commission  on January 7,
                  2005)
   
   10.28          Modification  Agreement,  dated as of January 3, 2005,  by and
                  between Natural Gas Services Group,  Inc. and Western National
                  Bank  (Incorporated  by  reference  to  Exhibit  10.2  of  the
                  Registrant's  Current  Report on Form 8-K,  dated  January  3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)
   
   10.29          Guaranty  Agreement,  dated as of  January  3,  2005,  made by
                  Natural Gas Service  Group,  Inc.,  for the benefit of Western
                  National  Bank  (Incorporated  by reference to Exhibit 10.3 of
                  the Registrant's  Current Report on Form 8-K, dated January 3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)
   
   10.30          Guaranty Agreement, dated as of January 3, 2005, made by Screw
                  Compression Systems, Inc., for the benefit of Western National
                  Bank  (Incorporated  by  reference  to  Exhibit  10.4  of  the
                  Registrant's  Current  Report on Form 8-K,  dated  January  3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)
   
   

                                                                              15


   10.31          Third Amended and Restated  Loan  Agreement  (Incorporated  by
                  reference to Exhibit 10.1 of the  Registrant's  Form 8-K dated
                  January 3, 2005 and filed  with the  Securities  and  Exchange
                  Commission January 3, 2005)

    10.32         First   Modification  to  Fourth  Amended  and  Restated  Loan
                  Agreement  (Incorporated  by  reference  Exhibit  10.1  of the
                  Registrant's  Form  8-K  dated  May 1,  2005  and  filed  with
                  Securities and Exchange Commission May 13, 2005)


   14.0           Code of Ethics  (Incorporated  by reference to Exhibit 14.0 of
                  the  Registrant's  Form  10-KSB  for  the  fiscal  year  ended
                  December 31, 2004,  and filed with the Securities and Exchange
                  Commission on March 30, 2005)
   
   21.0           Subsidiaries (Incorporated by reference to Exhibit 21.0 of the
                  Registrant's  Form 10-KSB for the fiscal  year ended  December
                  31,  2004,   and  filed  with  the   Securities  and  Exchange
                  Commission on March 30, 2005)
   
   
   *31.1          Certification  of Chief Executive  Officer required by Section
                  302 of the Sarbanes-Oxley Act of 2002
   
   *31.2          Certification  of Chief Financial  Officer required by Section
                  302 of the Sarbanes-Oxley Act of 2002
   
   *32.1          Certification  required by Section  906 of the  Sarbanes-Oxley
                  Act of 2002
   
   *32.2          Certification  required by Section  906 of the  Sarbanes-Oxley
                  Act of 2002


                           

 * Filed herewith.






                                                                              16



                                   SIGNATURES

                  In accordance  with the  requirements of the Exchange Act, the
registrant  caused  this  report to be signed on its behalf by the  undersigned,
thereunto duly authorized.


NATURAL GAS SERVICES GROUP, INC.


By:  /s/ Stephen Taylor
    -----------------------------
    Stephen Taylor
    President and Chief Executive
    Officer

By:  /s/ Earl R. Wait
   ------------------------------ 
   Earl R. Wait
   Chief Financial Officer
   And Treasurer

May 16, 2005
























                                                                              17


                               INDEX TO EXHIBITS:

Exhibit No.                                Description
-----------                                -----------


   2.1            Purchase and Sale Agreement by and between Hy-Bon  Engineering
                  Company, Inc. and NGE Leasing, Inc. (Incorporated by reference
                  to Exhibit 2.1 of the Registrant's  Current Report on Form 8-K
                  dated  February  28,  2003 and filed with the  Securities  and
                  Exchange Commission on March 6, 2003)
   
   3.1            Articles  of  Incorporation,   as  amended   (Incorporated  by
                  reference to Exhibit 3.1 of the 10QSB filed and dated November
                  10, 2004)
   
   3.2            Bylaws  (Incorporated  by  reference  to  Exhibit  3.4  of the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   4.1            Form of warrant  certificate  (Incorporated  by  reference  to
                  Exhibit 4.1 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.2            Form of warrant agent agreement  (Incorporated by reference to
                  Exhibit 4.2 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.3            Form  of  lock-up  agreement  (Incorporated  by  reference  to
                  Exhibit 4.3 of the Registrant's Registration Statement on Form
                  SB-2, No. 333-88314)
   
   4.4            Form of  representative's  option for the  purchase  of common
                  stock  (Incorporated  by  reference  to  Exhibit  4.4  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
 
   4.5            Form of  representative's  option for the purchase of warrants
                  (Incorporated  by reference to Exhibit 4.5 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   4.6            Stockholders  Agreement,  dated  January 3, 2005 among Paul D.
                  Hensley,  Tony Vohjesus,  Jim Hazlett and Natural Gas Services
                  Group,  Inc.  (Incorporated by reference to Exhibit 4.3 of the
                  Registrant's From 8-K Report,  dated January 3, 2005, as filed
                  with the  Securities  and  Exchange  Commission  on January 7,
                  2005)   
                                                                        
                  Executive  Compensation Plans and Arrangements (Exhibits 10.1,
                  10.24, 10.25 and 10.26)
   
   10.1           1998 Stock Option Plan  (Incorporated  by reference to Exhibit
                  10.1 of the Registrant's  Registration Statement on Form SB-2,
                  No. 333-88314)
   
   10.2           Asset Purchase  Agreement,  dated January 1, 2001, between the
                  Registrant and Great Lakes Compression,  Inc. (Incorporated by
                  reference  to Exhibit  10.2 of the  Registrant's  Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.3           Exhibits  3(c)(1),  3(c)(2),   3(c)(3),   3(c)(4),   13(d)(1),
                  13(d)(2)  and  13(d)(3)  to Asset  Purchase  Agreement,  dated
                  January  1,  2001,  between  the  Registrant  and Great  Lakes
                  Compression,  Inc. (Incorporated by reference to Exhibit 10.14
                  of the Registrant's  Registration  Statement on Form SB-2, No.
                  333-88314)
   


                                                                              18


   10.4           Amendment to Guaranty  Agreement  between Natural Gas Services
                  Group, Inc. and Dominion Michigan  Production  Services,  Inc.
                  (Incorporated by reference to Exhibit 10.3 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.5           Form of Series A 10% Subordinated  Notes due December 31, 2006
                  (Incorporated by reference to Exhibit 10.8 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.6           Form  of   Five-Year   Warrants  to  Purchase   Common   Stock
                  (Incorporated by reference to Exhibit 10.9 of the Registrant's
                  Registration Statement on Form SB-2, No. 333-88314)
   
   10.7           Warrants issued to Berry-Shino Securities,  Inc. (Incorporated
                  by reference to Exhibit 10.10 of the Registrant's Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.8           Warrants   issued   to   Neidiger,    Tucker,   Bruner,   Inc.
                  (Incorporated   by   reference   to   Exhibit   10.11  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   10.9           Form of  warrant  issued in March 2001 for  guaranteeing  debt
                  (Incorporated   by   reference   to   Exhibit   10.12  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)

   10.10          Form of  warrant  issued in April 2002 for  guaranteeing  debt
                  (Incorporated   by   reference   to   Exhibit   10.13  of  the
                  Registrant's   Registration   Statement  on  Form  SB-2,   No.
                  333-88314)
   
   10.11          Articles of Organization of Hy-Bon Rotary Compression, L.L.C.,
                  dated April 17, 2000  (Incorporated  by  reference  to Exhibit
                  10.18 of the Registrant's Registration Statement on Form SB-2,
                  No. 333-88314)
   
   10.12          Regulations of Hy-Bon Rotary Compression, L.L.C. (Incorporated
                  by reference to Exhibit 10.19 of the Registrant's Registration
                  Statement on Form SB-2, No. 333-88314)
   
   10.13          First  Amended  and  Restated  Loan   Agreement   between  the
                  Registrant  and  Western   National  Bank   (Incorporated   by
                  reference to Exhibit 10.1 of the  Registrant's  Current Report
                  on  Form  8-K,  dated  March  27,  2003  and  filed  with  the
                  Securities and Exchange Commission on April 14, 2003)
   
   10.14          Form of Termination of Employment Agreement Letter relating to
                  the  Employment  Agreement  of  Alan  Kurus  (Incorporated  by
                  reference to Exhibit 10.25 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   


                                                                              19


   10.15          Form of Termination of Employment Agreement Letter relating to
                  the  Employment  Agreement  of Wayne Vinson  (Incorporated  by
                  reference to Exhibit 10.26 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   
   10.16          Form of Termination of Employment Agreement Letter relating to
                  the  Employment   Agreement  of  Earl  Wait  (Incorporated  by
                  reference to Exhibit 10.27 of the  Registrant's  Annual Report
                  on Form 10-KSB for the fiscal year ended December 31, 2002)
   
   10.17          Triple Net Lease  Agreement,  dated June 1, 2003,  between NGE
                  Leasing, Inc. and Steven J. & Katherina L. Winer (Incorporated
                  by  reference  to  Exhibit  10.17 of the  Registrant's  Annual
                  Report on Form 10-KSB for the fiscal year ended  December  31,
                  2003)
   
   10.18          Lease  Agreement,  dated June 19,  2003,  between NGE Leasing,
                  Inc. and Wise Commercial Properties (Incorporated by reference
                  to Exhibit  10.18 of the  Registrant's  Annual  Report on Form
                  10-KSB for the fiscal year ended December 31, 2003)
   
   10.19          Lease Agreement,  dated March 1, 2004,  between the Registrant
                  and the City of Midland,  Texas  (Incorporated by reference to
                  Exhibit 10.19 of the  Registrant's  Form 10-QSB for the fiscal
                  quarter ended June 30, 2004)
   
   10.20          Second Amended and Restated Loan Agreement,  dated November 3,
                  2003,   between  the  Registrant  and  Western  National  Bank
                  (Incorporated   by   reference   to   Exhibit   10.20  of  the
                  Registrant's Form 10-QSB for the fiscal quarter ended June 30,
                  2004)

   10.21          Securities  Purchase  Agreement,  dated July 20, 2004, between
                  the Registrant and CBarney Investments,  Ltd. (Incorporated by
                  reference to Exhibit 4.1 of the Registrant's Current Report on
                  Form 8-K dated July 20, 2004 and filed with the Securities and
                  Exchange Commission on July 27, 2004)
   
   10.22          Stock Purchase Agreement, dated October 18, 2004, by and among
                  the  Registrant,  Screw  Compression  Systems,  Inc.,  Paul D.
                  Hensley,  Jim  Hazlett  and  Tony  Vohjesus  (Incorporated  by
                  reference to Exhibit 4.1 of the Registrant's Current Report on
                  Form 8-K dated October 18, 2004 and filed with the  Securities
                  and Exchange Commission on October 21, 2004)
   
   10.23          Fourth  Amended and Restated Loan Agreement  (Incorporated  by
                  reference to Exhibit 10.1 of the  Registrant's  Current Report
                  on Form 8-K, dated March 14, 2005 as filed with the Securities
                  and Exchange Commission on March 18, 2005)
   
   10.24          Employment  Agreement  between Paul D. Hensley and Natural Gas
                  Services  Group,  Inc.  (Incorporated  by reference to Exhibit
                  10.1 of the  Registrants  Form 8-K  Report,  dated  January 3,
                  2005, as filed with the Securities and Exchange  Commission on
                  January 7, 2005)
   
   10.25          Employment Agreement between William R. Larkin and Natural Gas
                  Services  Group,  Inc.  (Incorporated  by reference to Exhibit
                  10.25 of the  Registrant's  Form  10-KSB for the  fiscal  year
                  ended  December 31, 2004,  and filed with the  Securities  and
                  Exchange Commission on March 30, 2005)
   


                                                                              20


   10.26          Promissory  Note,  dated  January  3,  2005,  in the  original
                  principal amount of $2,100,000.00 made by Natural Gas Services
                  Group,  Inc.  payable  to Paul  D.  Hensley  (Incorporated  by
                  reference to Exhibit 10.26 of the Registrant's Form 10-KSB for
                  the fiscal year ended  December 31,  2004,  and filed with the
                  Securities and Exchange Commission on March 30, 2005)
   
   10.27          Third Amended and Restated Loan Agreement, dated as of January
                  3,  2005,  among  Natural  Gas  Services  Group,  Inc.,  Screw
                  Compression   Systems,   Inc.   and  Western   National   Bank
                  (Incorporated by reference to Exhibit 10.1 of the Registrant's
                  current  Report on form 8-K,  dated January 3, 2005, and filed
                  with the  Securities  and  Exchange  Commission  on January 7,
                  2005)
   
   10.28          Modification  Agreement,  dated as of January 3, 2005,  by and
                  between Natural Gas Services Group,  Inc. and Western National
                  Bank  (Incorporated  by  reference  to  Exhibit  10.2  of  the
                  Registrant's  Current  Report on Form 8-K,  dated  January  3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)
   
   10.29          Guaranty  Agreement,  dated as of  January  3,  2005,  made by
                  Natural Gas Service  Group,  Inc.,  for the benefit of Western
                  National  Bank  (Incorporated  by reference to Exhibit 10.3 of
                  the Registrant's  Current Report on Form 8-K, dated January 3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)
   
   10.30          Guaranty Agreement, dated as of January 3, 2005, made by Screw
                  Compression Systems, Inc., for the benefit of Western National
                  Bank  (Incorporated  by  reference  to  Exhibit  10.4  of  the
                  Registrant's  Current  Report on Form 8-K,  dated  January  3,
                  2005, and filed with the Securities and Exchange Commission on
                  January 7, 2005)

   10.31          Third Amended and Restated  Loan  Agreement  (Incorporated  by
                  reference to Exhibit 10.1 of the  Registrant's  Form 8-K dated
                  January 3, 2005 and filed  with the  Securities  and  Exchange
                  Commission January 3, 2005)

    10.32         First   Modification  to  Fourth  Amended  and  Restated  Loan
                  Agreement  (Incorporated  by  reference  Exhibit  10.1  of the
                  Registrant's  Form  8-K  dated  May 1,  2005  and  filed  with
                  Securities and Exchange Commission May 13, 2005)


   14.0           Code of Ethics  (Incorporated  by reference to Exhibit 14.0 of
                  the  Registrant's  Form  10-KSB  for  the  fiscal  year  ended
                  December 31, 2004,  and filed with the Securities and Exchange
                  Commission on March 30, 2005)
   
   21.0           Subsidiaries (Incorporated by reference to Exhibit 21.0 of the
                  Registrant's  Form 10-KSB for the fiscal  year ended  December
                  31,  2004,   and  filed  with  the   Securities  and  Exchange
                  Commission on March 30, 2005)
   
   

                                                                              21

                          
   *31.1          Certification  of Chief Executive  Officer required by Section
                  302 of the Sarbanes-Oxley Act of 2002
   
   *31.2          Certification  of Chief Financial  Officer required by Section
                  302 of the Sarbanes-Oxley Act of 2002
   
   *32.1          Certification  required by Section  906 of the  Sarbanes-Oxley
                  Act of 2002
   
   *32.2          Certification  required by Section  906 of the  Sarbanes-Oxley
                  Act of 2002


-------------------------
 * Filed herewith.