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UNITEDSTATES
SECURITIESANDEXCHANGECOMMISSION
Washington,D.C.20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number 811-21972

Name of Fund: BlackRock Credit Allocation Income Trust IV (BTZ)

Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: Anne F. Ackerley, Chief Executive Officer, BlackRock
Credit Allocation Income Trust IV, 55 East 52nd Street, New York, NY 10055.

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 10/31/2010

Date of reporting period: 01/31/2010

Item 1 – Schedule of Investments

Schedule of Investments January 31, 2010 (Unaudited)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

Common Stocks  Shares  Value 
Aerospace & Defense — 0.1%     
Honeywell International, Inc.  1,800  $ 69,552 
Lockheed Martin Corp.  3,800  283,176 
Northrop Grumman Corp.  5,200  294,320 
United Technologies Corp.  1,800  121,464 
    768,512 
Air Freight & Logistics — 0.1%     
United Parcel Service, Inc., Class B (a)  8,800  508,376 
Auto Components — 0.0%     
Johnson Controls, Inc.  3,700  102,971 
Beverages — 0.2%     
The Coca-Cola Co.  14,300  775,775 
PepsiCo, Inc.  5,800  345,796 
    1,121,571 
Biotechnology — 0.2%     
Amgen, Inc. (b)  6,900  403,512 
Biogen Idec, Inc. (b)  2,500  134,350 
Celgene Corp. (b)  3,500  198,730 
Genzyme Corp. (b)  1,700  92,242 
Gilead Sciences, Inc. (b)  7,100  342,717 
    1,171,551 
Capital Markets — 0.1%     
Federated Investors, Inc., Class B  6,700  170,046 
The Goldman Sachs Group, Inc.  1,360  202,259 
Morgan Stanley  3,000  80,340 
    452,645 
Chemicals — 0.2%     
Air Products & Chemicals, Inc.  900  68,364 
E.I. du Pont de Nemours & Co. (a)  14,800  482,628 
Monsanto Co.  2,900  220,052 
PPG Industries, Inc.  3,900  228,852 
    999,896 
Commercial Banks — 0.9%     
Citizens Banking Corp. (b)  6,406,596  4,869,013 
M&T Bank Corp.  4,200  309,750 
Regions Financial Corp.  38,400  243,840 
Wells Fargo & Co.  33,300  946,719 
    6,369,322 
Commercial Services & Supplies — 0.1%     
Avery Dennison Corp.  7,900  256,829 
Pitney Bowes, Inc.  10,800  225,936 
Waste Management, Inc.  7,700  246,785 
    729,550 
Communications Equipment — 0.2%     
Cisco Systems, Inc. (b)  23,400  525,798 
Motorola, Inc.  34,800  214,020 
QUALCOMM, Inc.  8,900  348,791 
    1,088,609 
Computers & Peripherals — 0.4%     
Apple, Inc. (b)  6,000  1,152,720 
Dell, Inc. (b)  14,900  192,210 
EMC Corp. (b)  13,900  231,713 

Common Stocks  Shares  Value 
Computers & Peripherals (concluded)     
Hewlett-Packard Co.  8,800  $ 414,216 
International Business Machines Corp.  5,800  709,862 
    2,700,721 
Distributors — 0.0%     
Genuine Parts Co.  7,300  275,064 
Diversified Financial Services — 0.2%     
Bank of America Corp.  36,800  558,624 
JPMorgan Chase & Co.  21,100  821,634 
NYSE Euronext  9,100  213,031 
    1,593,289 
Diversified Telecommunication Services — 0.3%   
AT&T, Inc.  38,887  986,174 
CenturyTel, Inc.  4,339  147,570 
Verizon Communications, Inc.  20,900  614,878 
    1,748,622 
Electric Utilities — 0.1%     
American Electric Power Co., Inc.  2,200  76,230 
Duke Energy Corp.  20,200  333,906 
FirstEnergy Corp.  1,300  56,706 
Progress Energy, Inc.  5,400  210,438 
The Southern Co.  8,700  278,400 
    955,680 
Electrical Equipment — 0.1%     
Emerson Electric Co. (a)  10,900  452,786 
Rockwell Automation, Inc.  5,400  260,496 
    713,282 
Electronic Equipment, Instruments & Components — 0.0%   
Corning, Inc.  8,600  155,488 
Tyco Electronics Ltd.  5,200  129,376 
    284,864 
Energy Equipment & Services — 0.1%     
National Oilwell Varco, Inc.  5,600  229,040 
Schlumberger Ltd.  5,500  349,030 
Smith International, Inc.  5,418  164,274 
    742,344 
Food & Staples Retailing — 0.2%     
CVS Caremark Corp.  3,400  110,058 
SUPERVALU, Inc.  8,300  122,093 
SYSCO Corp.  9,600  268,704 
Wal-Mart Stores, Inc.  15,200  812,136 
Walgreen Co.  6,400  230,720 
    1,543,711 
Food Products — 0.1%     
Kraft Foods, Inc.  12,135  335,654 
Sara Lee Corp.  20,200  245,228 
    580,882 
Health Care Equipment & Supplies — 0.1%     
Baxter International, Inc.  1,900  109,421 
Becton Dickinson & Co.  3,400  256,258 
Boston Scientific Corp. (b)  5,900  50,917 
Covidien Plc  5,200  262,912 

BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010 1

Schedule of Investments (continued)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

Common Stocks  Shares  Value 
Health Care Equipment & Supplies     
(concluded)     
Medtronic, Inc.  2,000  $ 85,780 
    765,288 
Health Care Providers & Services — 0.2%     
Aetna, Inc.  2,400  71,928 
Express Scripts, Inc. (b)  3,400  285,124 
Medco Health Solutions, Inc. (b)  4,300  264,364 
UnitedHealth Group, Inc.  2,400  79,200 
WellPoint, Inc. (b)  4,500  286,740 
    987,356 
Hotels, Restaurants & Leisure — 0.1%     
McDonald's Corp.  8,700  543,141 
Starwood Hotels & Resorts     
Worldwide, Inc.  12,300  409,836 
    952,977 
Household Durables — 0.2%     
Black & Decker Corp.  5,700  368,562 
Fortune Brands, Inc.  6,400  266,048 
KB Home  15,100  230,728 
Whirlpool Corp. (a)  5,800  436,044 
    1,301,382 
Household Products — 0.2%     
Clorox Co.  4,200  248,514 
The Procter & Gamble Co.  17,400  1,070,970 
    1,319,484 
IT Services — 0.1%     
Automatic Data Processing, Inc.  6,700  273,293 
Cognizant Technology Solutions     
Corp. (b)  3,400  148,444 
MasterCard, Inc., Class A  409  102,209 
Paychex, Inc.  9,700  281,203 
    805,149 
Industrial Conglomerates — 0.3%     
3M Co. (a)  6,900  555,381 
General Electric Co.  43,400  697,872 
Textron, Inc. (a)  23,400  457,002 
    1,710,255 
Insurance — 0.3%     
Aflac, Inc. (a)  10,600  513,358 
The Allstate Corp.  8,700  260,391 
Cincinnati Financial Corp.  8,500  224,315 
Lincoln National Corp.  13,000  319,540 
MetLife, Inc.  10,600  374,392 
Principal Financial Group, Inc.  9,200  212,060 
    1,904,056 
Internet & Catalog Retail — 0.0%     
Amazon.com, Inc. (b)  810  101,582 
Internet Software & Services — 0.2%     
eBay, Inc. (b)  14,300  329,186 
Google, Inc., Class A (b)  1,160  614,127 
Yahoo! Inc. (b)  9,600  144,096 
    1,087,409 

Common Stocks  Shares  Value 
Leisure Equipment & Products — 0.0%     
Mattel, Inc.  11,600  $ 228,752 
Life Sciences Tools & Services — 0.0%     
Thermo Fisher Scientific, Inc. (b)  2,600  119,990 
Machinery — 0.1%     
Caterpillar, Inc. (a)  8,500  444,040 
Cummins, Inc.  4,200  189,672 
Deere & Co.  2,800  139,860 
    773,572 
Media — 0.0%     
Comcast Corp., Class A  6,900  109,227 
DIRECTV, Class A (b)  6,400  194,240 
    303,467 
Metals & Mining — 0.1%     
Alcoa, Inc. (a)  24,500  311,885 
Nucor Corp.  5,400  220,320 
    532,205 
Multi-Utilities — 0.2%     
Consolidated Edison, Inc.  5,400  236,196 
Dominion Resources, Inc.  2,200  82,412 
Integrys Energy Group, Inc.  5,500  230,175 
Public Service Enterprise Group, Inc.  7,900  241,661 
TECO Energy, Inc.  8,900  138,573 
Xcel Energy, Inc.  10,400  216,112 
    1,145,129 
Multiline Retail — 0.0%     
Macy's, Inc.  18,400  293,112 
Oil, Gas & Consumable Fuels — 0.8%     
Anadarko Petroleum Corp.  5,000  318,900 
Apache Corp.  1,800  177,786 
Chevron Corp.  13,400  966,408 
ConocoPhillips  13,000  624,000 
Exxon Mobil Corp.  27,800  1,791,154 
Hess Corp.  3,700  213,823 
Massey Energy Co.  5,400  208,008 
Occidental Petroleum Corp.  1,700  133,178 
Peabody Energy Corp.  5,500  231,660 
Southwestern Energy Co. (b)  5,500  235,840 
Spectra Energy Corp.  14,700  312,375 
XTO Energy, Inc.  6,900  307,533 
    5,520,665 
Paper & Forest Products — 0.1%     
MeadWestvaco Corp.  15,300  368,271 
Weyerhaeuser Co.  5,600  223,440 
    591,711 
Pharmaceuticals — 0.6%     
Abbott Laboratories  10,400  550,576 
Bristol-Myers Squibb Co.  17,800  433,608 
Eli Lilly & Co.  9,900  348,480 
Johnson & Johnson  17,900  1,125,194 
Merck & Co, Inc.  23,497  897,115 
Pfizer, Inc. (a)  31,504  587,865 
    3,942,838 

2 BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010

Schedule of Investments (continued)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

Common Stocks    Shares  Value 
Real Estate Investment Trusts (REITs) — 0.2%     
AvalonBay Communities, Inc.    4,200 $  321,762 
Boston Properties, Inc.    4,300  278,941 
Public Storage    1,200  95,016 
Vornado Realty Trust    4,996  323,141 
      1,018,860 
Road & Rail — 0.0%       
Norfolk Southern Corp.    5,900  277,654 
Semiconductors & Semiconductor Equipment — 0.2%   
Applied Materials, Inc.    5,200  63,336 
Intel Corp.    40,700  789,580 
Linear Technology Corp.    7,900  206,190 
Microchip Technology, Inc.    8,900  229,709 
National Semiconductor Corp.    9,500  125,970 
Texas Instruments, Inc.    9,300  209,250 
      1,624,035 
Software — 0.3%       
Autodesk, Inc. (b)    7,700  183,183 
Microsoft Corp.    46,100  1,299,098 
Oracle Corp. (a)    21,000  484,260 
      1,966,541 
Specialty Retail — 0.2%       
Home Depot, Inc. (a)    18,100  506,981 
Limited Brands, Inc.    16,100  306,222 
Staples, Inc.    12,300  288,558 
      1,101,761 
Textiles, Apparel & Luxury Goods — 0.0%     
VF Corp.    2,900  208,887 
Thrifts & Mortgage Finance — 0.0%       
Hudson City Bancorp, Inc.    19,000  252,130 
Tobacco — 0.2%       
Altria Group, Inc. (a)    20,500  407,130 
Philip Morris International, Inc.    16,600  755,466 
      1,162,596 
Total Common Stocks – 8.3%                                                   56,450,305
     Par   
Corporate Bonds    (000)   
Capital Markets — 0.0%       
Lehman Brothers Holdings, Inc.,       
   3.95%, 11/10/09 (b)(c)  $ 105  21,919 
Lehman Brothers Holdings, Inc.,       
   4.38%, 11/30/10 (b)(c)    325  67,843 
      89,762 
Communications Equipment — 0.5%       
Brocade Communications Systems,       
   Inc., 6.88%, 1/15/20 (d)    3,580  3,651,600 
Computers & Peripherals — 0.7%       
International Business Machines       
   Corp., 5.60%, 11/30/39    4,400  4,509,507 

     Par   
Corporate Bonds    (000)             Value 
Consumer Finance — 0.7%       
Capital One Bank USA NA, 8.80%,       
   7/15/19  $ 3,950  $ 4,790,046 
Diversified Financial Services — 2.6%       
Bank of America Corp., 7.63%,       
   6/01/19    8,025  9,181,659 
ING Groep NV, 5.78% (e)(f)    10,000  7,868,500 
Stan IV Ltd., 2.14%, 7/20/11 (f)    283  240,550 
      17,290,709 
Diversified Telecommunication Services — 0.3%     
Qwest Corp., 8.38%, 5/01/16    1,960  2,146,200 
Food Products — 0.6%       
Kraft Foods, Inc., 6.50%, 8/11/17    1,985  2,196,476 
Kraft Foods, Inc., 6.13%, 8/23/18    1,990  2,138,490 
      4,334,966 
Health Care Providers & Services — 1.3%     
Aetna, Inc., 6.75%, 12/15/37    4,075  4,578,071 
UnitedHealth Group, Inc., 6.88%,       
   2/15/38    4,075  4,549,852 
      9,127,923 
Hotels, Restaurants & Leisure — 0.4%       
Icahn Enterprises LP, 8.00%,       
   1/15/18 (d)    2,500  2,400,000 
Insurance — 2.5%       
Lincoln National Corp., 8.75%,       
   7/01/19    2,000  2,430,540 
Lincoln National Corp., 6.25%,       
   2/15/20    4,075  4,208,232 
Prudential Financial, Inc., 6.63%,       
   12/01/37    4,075  4,393,877 
QBE Insurance Group Ltd., 9.75%,       
   3/14/14 (d)    4,973  5,680,683 
      16,713,332 
Machinery — 0.7%       
Ingersoll-Rand Global Holding Co. Ltd.,       
   9.50%, 4/15/14    4,075  4,984,410 
Media — 2.1%       
COX Communications, Inc., 8.38%,       
   3/01/39 (d)    4,075  5,156,636 
Comcast Corp., 6.30%, 11/15/17    4,075  4,504,228 
UPC Germany GmbH, 8.13%,       
   12/01/17 (d)    1,225  1,237,250 
Virgin Media Secured Finance Plc,       
   6.50%, 1/15/18 (d)    3,175  3,123,406 
      14,021,520 
Metals & Mining — 0.0%       
Aleris International, Inc., 10.00%,       
   12/15/16 (b)(c)    5,000  50,000 
Multi-Utilities — 1.5%       
Dominion Resources, Inc., 8.88%,       
   1/15/19    8,000  10,142,208 

BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010 3

Schedule of Investments (continued)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

         Par   
Corporate Bonds    (000)  Value 
Oil, Gas & Consumable Fuels — 0.7%       
ONEOK Partners LP, 8.63%, 3/01/19  $ 4,075 $  5,088,265 
Paper & Forest Products — 2.2%       
Georgia-Pacific LLC, 8.25%,       
   5/01/16 (d)    2,030  2,172,100 
International Paper Co., 7.50%,       
   8/15/21    3,950  4,483,902 
International Paper Co., 8.70%,       
   6/15/38    3,100  3,858,896 
International Paper Co., 7.30%,       
   11/15/39    4,075  4,393,954 
      14,908,852 
Real Estate Investment Trusts (REITs) — 1.4%     
AvalonBay Communities, Inc., 6.10%,       
   3/15/20    4,075  4,320,091 
ERP Operating LP, 5.38%, 8/01/16    1,065  1,105,834 
ERP Operating LP, 5.75%, 6/15/17    4,080  4,224,640 
      9,650,565 
Tobacco — 1.5%       
Altria Group, Inc., 9.70%, 11/10/18    4,075  5,103,558 
Altria Group, Inc., 9.25%, 8/06/19    3,950  4,863,493 
      9,967,051 
Wireless Telecommunication Services — 0.4%   
Cricket Communications, Inc., 7.75%,       
   5/15/16    780  784,875 
Nextel Communications, Inc., Series E,       
   6.88%, 10/31/13    1,990  1,855,675 
      2,640,550 
Total Corporate Bonds – 20.1%                             136,507,466
Investment Companies    Shares   
UltraShort Real Estate ProShares    150,000  1,237,500 
Total Investment Companies – 0.2%      1,237,500 
Preferred Securities       
         Par   
Capital Trusts    (000)   
Building Products — 0.7%       
C8 Capital SPV Ltd., 6.64% (d)(e)(f)  $ 1,580  1,118,703 
C10 Capital SPV Ltd., 6.72% (d)(e)(f)    5,000  3,540,450 
      4,659,153 
Capital Markets — 2.9%       
Credit Suisse Guernsey Ltd.,       
   5.86% (e)(f)    1,050  924,000 

           Par   
Capital Trusts         (000)             Value 
Capital Markets (concluded)     
State Street Capital Trust III,     
   8.25% (e)(f)  $ 1,740  $ 1,780,542 
State Street Capital Trust IV, 1.25%,     
   6/01/67 (f)  25,245  17,298,556 
    20,003,098 
Commercial Banks — 14.8%     
BB&T Capital Trust IV, 6.82%,     
   6/12/77 (f)  15,300  13,770,000 
Bank of Ireland Capital Funding II, LP,     
   5.57% (d)(e)(f)  1,422  810,540 
Bank of Ireland Capital Funding III, LP,     
   6.11% (d)(e)(f)  9,153  5,217,210 
Barclays Bank Plc, 5.93% (d)(e)(f)  4,000  3,350,000 
Barclays Bank Plc, 6.86% (d)(e)(f)  11,500  9,602,500 
Commonwealth Bank of Australia,     
   6.02% (d)(e)(f)  20,000  17,291,200 
HSBC Capital Funding LP/Jersey     
   Channel Islands, 10.18% (d)(e)(f)  7,000  8,400,000 
Lloyds Banking Group Plc, 6.66% (d)(f)  10,000  6,000,000 
SMFG Preferred Capital USD 1 Ltd.,     
   6.08% (d)(e)(f)  10,000  9,518,700 
Shinsei Finance II, 7.16% (d)(e)(f)  1,005  618,390 
Standard Chartered Bank,     
   7.01% (d)(e)(f)  5,000  4,465,195 
USB Capital XIII Trust, 6.63%,     
   12/15/39  4,100  4,060,066 
Wells Fargo & Co., Series K,     
   7.98% (e)(f)  12,985  13,114,850 
Wells Fargo Capital XIII, Series GMTN,     
   7.70% (e)(f)  3,900  3,783,000 
    100,001,651 
Electric Utilities — 0.5%     
PPL Capital Funding, 6.70%,     
   3/30/67 (f)  3,900  3,412,500 
Insurance — 9.3%     
The Allstate Corp., 6.50%, 5/15/67 (f)  4,000  3,740,000 
AXA SA, 6.46% (d)(e)(f)  12,000  9,435,000 
Chubb Corp., 6.38%, 3/29/67 (f)  4,000  3,840,000 
Liberty Mutual Group, Inc., 10.75%,     
   6/15/88 (d)(f)  4,000  4,400,000 
Lincoln National Corp., 7.00%,     
   5/17/66 (f)  4,255  3,563,562 
MetLife, Inc., 6.40%, 12/15/66  4,550  4,004,000 
Nationwide Life Global Funding I,     
   6.75%, 5/15/67  4,000  3,219,028 
Progressive Corp., 6.70%, 6/15/67 (f)  4,000  3,680,000 
Reinsurance Group of America,     
   6.75%, 12/15/65 (f)  15,000  13,299,000 
Swiss Re Capital I LP, 6.85% (d)(e)(f)  3,000  2,578,539 
The Travelers Cos., Inc., 6.25%,     
   3/15/67 (f)  4,000  3,761,428 
White Mountains Re Group Ltd.,     
   7.51% (d)(e)(f)  4,400  3,750,472 

4 BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010

Schedule of Investments (continued)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

  Par   
Capital Trusts  (000)  Value 
Insurance (concluded)     
ZFS Finance, 5.88%, 5/09/32 (d)(f)  $ 599 $  511,732 
ZFS Finance, 6.50%, 5/09/67 (d)(f)  3,331  2,964,590 
    62,747,351 
Multi-Utilities — 0.2%     
Puget Sound Energy, Inc., Series A,     
   6.97%, 6/01/67 (f)  1,575  1,405,404 
Oil, Gas & Consumable Fuels — 1.2%     
Enterprise Products Operating LLC,     
   8.38%, 8/01/66 (f)  4,500  4,471,875 
TransCanada PipeLines Ltd., 6.35%,     
   5/15/67 (f)  4,000  3,796,540 
    8,268,415 
Real Estate Investment Trusts (REITs) — 1.7%   
Sovereign Real Estate Investment     
   Corp., 12.00% (d)(e)  10  11,212,500 
Total Capital Trusts – 31.3%                                  211,710,072
Preferred Stocks  Shares   
Commercial Banks — 5.5%     
HSBC USA, Inc., Series H, 6.50%  977,766  23,955,267 
Royal Bank of Scotland Group Plc,     
   Series M, 6.40%  15,000  175,050 
Santander Finance Preferred SA     
   Unipersonal, 10.50%  419,881  11,840,644 
Santander Perpetual SA Unipersonal,     
   6.67% (d)(f)  1,300,000  1,232,703 
    37,203,664 
Diversified Financial Services — 2.9%     
Cobank ACB, 7.00% (d)  150,000  5,700,000 
Falcons Funding Trust I, 8.88% (d)  5,650  5,650,000 
ING Groep NV, 6.13%  200,000  3,400,000 
ING Groep NV, 7.05%  5,800  112,172 
ING Groep NV, 7.20%  213  4,168,410 
ING Groep NV, 7.38%  40  808,917 
    19,839,499 
Diversified Telecommunication Services — 0.1%   
AT&T, Inc., 6.38%  30,000  786,510 
Electric Utilities — 4.2%     
Alabama Power Co., 6.50%  100,000  2,580,000 
Entergy Louisiana LLC, 6.95%  40,000  3,608,043 
Interstate Power & Light Co., Series B,     
   8.38%  785,000  22,254,750 
    28,442,793 
Insurance — 9.6%     
Aegon NV, 6.50%  400,000  7,468,000 
Arch Capital Group Ltd., Series B,     
   7.88%  160,000  3,958,400 
Arch Capital Group Ltd., Series A,     
   8.00%  100,000  2,495,000 

Preferred Stocks  Shares             Value 
Insurance (concluded)     
Aspen Insurance Holdings Ltd., 7.40%  655,000  $ 14,541,000 
Axis Capital Holdings Ltd., Series B,     
   7.50%  180,000  15,631,884 
Endurance Specialty Holdings Ltd.,     
   Series A, 7.75%  369,000  8,630,910 
PartnerRe Ltd., Series C, 6.75%  265,600  6,350,496 
RenaissanceRe Holdings Ltd., Series     
   D, 6.60%  285,000  6,167,400 
    65,243,090 
Real Estate Investment Trusts (REITs) — 0.5%     
BRE Properties, Inc., Series D, 6.75%  30,000  666,300 
iStar Financial, Inc., Series I, 7.50%  55,000  580,250 
Public Storage, Series F, 6.45%  30,000  663,900 
Public Storage, Series M, 6.63%  55,000  1,255,100 
    3,165,550 
Wireless Telecommunication Services — 1.5%     
Centaur Funding Corp., 9.08% (d)  10,000  10,387,500 
Total Preferred Stocks – 24.3%    165,068,606 
  Shares   
Trust Preferred  (000)   
Capital Markets — 0.0%     
Credit Suisse Guernsey Ltd., 7.90%,     
   3/28/13 (e)  10  255,122 
Commercial Banks — 3.3%     
Kazkommerts Finance 2 BV, 9.20%,     
   11/29/49 (e)(f)  500  430,000 
Mizuho Capital Investment 1 Ltd.,     
   6.69% (d)(e)(f)  21,000  17,891,013 
National City Preferred Capital Trust I,     
   12.00% (e)(f)  3,713  4,226,359 
    22,547,372 
Diversified Financial Services — 3.5%     
JPMorgan Chase Capital XXI, Series U,     
   1.20%, 1/15/87 (f)  12,875  8,989,274 
JPMorgan Chase Capital XXIII, 1.25%,     
   5/15/77 (f)(g)  20,695  14,492,812 
    23,482,086 
Electric Utilities — 1.1%     
PPL Energy Supply LLC, 7.00%,     
   7/15/46  288  7,370,560 
Insurance — 1.9%     
Ace Capital Trust II, 9.70%, 4/01/30  4,000  4,738,136 
Aon Corp., 8.21%, 1/01/27  4,000  4,144,400 
W.R. Berkley Capital Trust II, 6.75%,     
   7/26/45  171  3,946,492 
    12,829,028 
Media — 7.0%     
Comcast Corp., 6.63%, 5/15/56  1,950  47,027,171 

BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010 5

Schedule of Investments (continued)

BlackRock Credit Allocation Income Trust IV (BTZ)
(Percentages shown are based on Net Assets)

  Shares   
Trust Preferred  (000)  Value 
Oil, Gas & Consumable Fuels — 0.4%     
Nexen, Inc., 7.35%, 11/01/43  120 $  2,835,615 
Total Trust Preferred – 17.2%    116,346,954 
Total Preferred Securities – 72.8%    493,125,632 
Total Long-Term Investments     
(Cost – $740,756,340) – 101.4%                           687,320,903
Short-Term Securities  Shares   
BlackRock Liquidity Funds, TempFund,     
   Institutional Class, 0.10% (h)(i)  259,511,408  259,511,408 
Total Short-Term Securities     
(Cost – $259,511,408) – 38.3%    259,511,408 
Options Purchased  Contracts   
Exchange-Traded Put Options — 0.0%     
10-Year U.S. Treasury Bond Future,     
   Strike price $116.50, Expires     
   2/19/10  206  32,187 
Total Options Purchased     
(Cost – $42,018) – 0.0%    32,187 
Total Investments Before Outstanding     
Options Written     
(Cost – $1,000,309,766*) – 139.7%    946,864,498 
Options Written     
Exchange-Traded Call Options — 0.0%     
S&P 500 Listed Option,     
   Strike price $112,     
   Expires 2/20/10  50  (18,750) 
S&P 500 Listed Option,     
   Strike price $114,     
   Expires 2/20/10  427  (58,713) 
S&P 500 Listed Option,     
   Strike price $114.50,     
   Expires 2/20/10  95  (9,500) 
S&P 500 Listed Option,     
   Strike price $115,     
   Expires 2/20/10  48  (3,240) 
Total Options Written     
(Premiums Received – $1,203,438) – 0.0%  (90,203) 

                Value 
Total Investments, Net of Outstanding         
Options Written – 139.7%      $ 946,774,295 
Liabilities in Excess of Other Assets – (5.6)%    (37,889,435) 
Preferred Shares, at Redemption Value – (34.1)%  (231,060,005) 
Net Assets – 100.0%        $ 677,824,855 
*     The cost and unrealized appreciation (depreciation) of investments as of 
     January 31, 2010, as computed for federal income tax purposes, were as 
     follows:               
     Aggregate cost        $ 1,013,478,804 
     Gross unrealized appreciation      $ 35,450,178 
     Gross unrealized depreciation        (102,064,484) 
     Net unrealized depreciation      $ (66,614,306) 
(a)     All or a portion of security has been pledged as collateral in connection 
     with open financial futures contracts.       
(b)     Non-income producing security.           
(c)     Issuer filed for bankruptcy and/or is in default of interest payments. 
(d)     Security exempt from registration under Rule 144A of the Securities Act 
     of 1933. These securities may be resold in transactions exempt from 
     registration to qualified institutional investors.     
(e)     Security is perpetual in nature and has no stated maturity date. 
(f)     Variable rate security. Rate shown is as of report date.   
(g)     All or a portion of the security has been pledged as collateral in connection 
     with open financial futures contracts.       
(h)     Investments in companies considered to be an affiliate of the Fund, for 
     purposes of Section 2(a)(3) of the Investment Company Act of 1940, 
     were as follows:             
            Net     
     Affiliate          Activity    Income 
     BlackRock Liquidity Funds,           
     TempFund, Institutional Class    $ (8,321,373)  $ 114,192 
(i)     Represents the current yield as of report date.     
•  For Fund compliance purposes, the Fund’s industry classifications refer to any 
  one or more of the industry sub-classifications used by one or more widely 
  recognized market indexes or ratings group indexes, and/or as defined by 
  Fund management. This definition may not apply for purposes of this report, 
  which may combine industry sub-classifications for reporting ease. 
• Reverse repurchase agreements outstanding as of January 31, 2010 were as 
   follows:               
  Counter-      Interest     Trade  Maturity  Net Closing      Face 
      party   Rate    Date  Date  Amount    Amount 
   Barclays                  
     Bank Plc  0.05%  2/22/10           3/22/10  $(49,773,622) $  43,845,564 
• Financial futures contracts purchased as of January 31, 2010 were as 
   follows:               
      Expiration    Notional   Unrealized 
      Contracts  Issue  Date    Value    Depreciation 
       401  10-Year             
    U.S.             
    Treasury  March           
    Bond  2010  $ 47,469,237 $      (270,284) 
  33  30-Year             
    U.S.             
    Treasury             
    Bond  March 2010$  3,945,574          (46,418) 
       801  S&P EMINI        March 2010               $ 44,576,321       (1,354,361) 
   Total                                          $ (1,671,063) 

6 BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010

Investments BlackRock Credit Allocation Income Trust IV (BTZ)
Schedule of January 31, 2010 (Unaudited)

•  Credit default swaps on single-name issues – buy protection outstanding as of 
  January 31, 2010 were as follows:       
    Pay      Notional   
    Fixed  Counter-    Amount  Unrealized 
  Issuer  Rate  party  Expiration  (000)  Depreciation 
  Nordstrom,    Deutsche  June     
  Inc.  5.20%  Bank AG  2014  $ 4,000  $ (729,302) 
•  Fair Value Measurements — Various inputs are used in determining the 
  fair value of investments, which are as follows:     
   • Level 1 — price quotations in active markets/exchanges for identical 
       assets and liabilities         
   • Level 2 — other observable inputs (including, but not limited to: quoted 
       prices for similar assets or liabilities in markets that are active, quoted 
       prices for identical or similar assets or liabilities in markets that are not 
       active, inputs other than quoted prices that are observable for the 
       assets or liabilities (such as interest rates, yield curves, volatilities, 
       repayment speeds, loss severities, credit risks and default rates) or 
       other market-corroborated inputs)     
   • Level 3 — unobservable inputs based on the best information available 
       in the circumstances, to the extent observable inputs are not available 
       (including the Fund’s own assumptions used in determining the fair 
       value of investments)         
  The inputs or methodologies used for valuing securities are not 
  necessarily an indication of the risk associated with investing in those 
  securities. For information about the Fund’s policy regarding valuation of 
  investments and other significant accounting policies, please refer to the 
  Fund’s most recent financial statements as contained in its annual report. 
  The following table summarizes the inputs used as of January 31, 2010 in 
  determining the fair valuation of the Fund’s investments:   
          Investments in 
  Valuation Inputs        Securities 
             Assets 
  Level 1           
     Long-Term Investments:       
         Common Stocks      $ 56,450,305 
         Investment Companies      1,237,500 
         Preferred Stocks        122,858,476 
         Trust Preferreds        61,434,960 
     Short-Term Securities        259,511,408 
  Total Level 1          501,492,649 
  Level 2           
     Long-Term Investments:       
         Corporate Bonds        136,266,916 
         Capital Trusts        211,710,072 
         Preferred Stocks        36,560,130 
         Trust Preffereds        54,911,994 
  Total Level 2          439,449,112 
  Level 3           
     Long-Term Investments:       
         Corporate Bonds        240,550 
         Preferred Stocks        5,650,000 
  Total Level 3          5,890,550 
  Total        $ 946,832,311 

Valuation               Other Financial Instruments1 
Inputs  Assets  Liabilities 
Level 1  $ 32,187  $ (1,761,266) 
Level 2  -  (729,302) 
Level 3  -  - 
Total  $ 32,187  $ (2,490,568) 
 1Other financial instruments are financial futures contracts, swaps and 
   options. Financial futures contracts and swaps are shown as the 
   unrealized appreciation/depreciation on the instruments and options are 
   shown at market value.     

BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010 7

Schedule Investments BlackRock Credit Allocation Income Trust IV (BTZ)
of (concluded)

The following table is a reconciliation of level 3 investments for which significant unobservable inputs were used in determining fair 
value:         
    Investments in Securities   
  Preferred  Corporate     
  Stocks  Bonds    Total 
Balance, as of October 31, 2009  -  $ 240,550 $  240,550 
Accrued discounts/premiums  -   -                - 
Realized gain (loss)  -   -           - 
Change in unrealized         
appreciation/depreciation2  -   -         - 
Net purchases (sales)  -   -        - 
Net transfers in/out of Level 3  $ 5,650,000   -      5,650,000 
Balance, as of January 31, 2010  $ 5,650,000  $ 240,550 $  5,890,550 
 2The change in unrealized appreciation/depreciation on securities still     
   held at January 31, 2010 was $0.         

8 BlackRock Credit Allocation Income Trust IV JANUARY 31, 2010

Item 2 – Controls and Procedures

2(a) – The registrant's principal executive and principal financial officers or persons performing
similar functions have concluded that the registrant's disclosure controls and procedures (as
defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the
“1940 Act”)) are effective as of a date within 90 days of the filing of this report based on the
evaluation of these controls and procedures required by Rule 30a-3(b) under the 1940 Act
and Rule 13(a)-15(b) under the Securities Exchange Act of 1934, as amended.

2(b) – There were no changes in the registrant's internal control over financial reporting (as defined
in Rule 30a-3(d) under the 1940 Act) that occurred during the registrant's last fiscal quarter
that have materially affected, or are reasonably likely to materially affect, the registrant's
internal control over financial reporting.

Item 3 – Exhibits

Certifications – Attached hereto

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by
the undersigned, thereunto duly authorized.

BlackRock Credit Allocation Income Trust IV

By: /s/ Anne F. Ackerley
Anne F. Ackerley
Chief Executive Officer of
BlackRock Credit Allocation Income Trust IV

Date: March 19, 2010

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment
Company Act of 1940, this report has been signed below by the following persons on behalf
of the registrant and in the capacities and on the dates indicated.

By: /s/ Anne F. Ackerley
Anne F. Ackerley
Chief Executive Officer (principal executive officer) of
BlackRock Credit Allocation Income Trust IV

Date: March 19, 2010

By: /s/ Neal J. Andrews
Neal J. Andrews
Chief Financial Officer (principal financial officer) of
BlackRock Credit Allocation Income Trust IV

Date: March 19, 2010