Blackrock California Municipal Series Trust NPORT-P BlackRock California Municipal Opportunities Fund (Feb 2021 report)

Schedule of Investments  (unaudited)  February 28, 2021 BlackRock California Municipal Opportunities Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Corporate Bonds
Education — 0.0%
University of Southern California, 3.03%, 10/01/39	$	650	$	680,399
Tobacco — 0.2%
Altria Group, Inc., 3.70%, 02/04/51		7,915		7,400,182
Total Corporate Bonds — 0.2% (Cost: $8,450,009)				8,080,581
Municipal Bonds
California — 78.7%
Corporate — 0.0%
City of Chula Vista CA, RB, 1.41%, 06/01/28		1,400		1,378,496
County/City/Special District/School District — 33.4%
Butte-Glenn Community College District, GO, Series A, Election 2016, 5.25%, 08/01/46		12,360		15,203,294
California Statewide Communities Development Authority, SAB
Series A, 5.00%, 09/02/39		1,375		1,595,261
Series A, 5.00%, 09/02/44		675		762,750
Series A, 5.00%, 09/02/48		675		755,669
Cerritos Community College District, GO, Series A, 4.00%, 08/01/44		36,455		39,607,628
Chaffey Community College District GO, Series A, 3.00%, 06/01/37		2,500		2,700,600
City & County of San Francisco CA, GO
Series D-1, 4.00%, 06/15/44		4,970		5,711,126
Series D-1, 4.00%, 06/15/45		5,165		5,862,895
City & County of San Francisco California Community Facilities District No. 2014-1, ST
Series B, 3.78%, 09/01/30		1,110		1,241,402
Series B, 3.92%, 09/01/31		3,410		3,828,680
Series B, 3.97%, 09/01/32		1,880		2,108,834
Series B, 4.02%, 09/01/33		2,070		2,320,097
City & County of San Francisco California, Refunding COP, Series A, 4.00%, 04/01/42		8,000		8,889,360
City & County of San Francisco GOL, Series D-1, 4.00%, 06/15/37		2,295		2,685,540
City & County of San Francisco, GO, Series D-1, 4.00%, 06/15/41		1,655		1,906,378
City of Los Angeles California, COP, (AMBAC), 6.20%, 11/01/31		3,800		3,816,948
City of Los Angeles California, RB, 4.00%, 06/24/21		64,000		64,769,920
City of San Jose California Hotel Tax Revenue, RB, 6.50%, 05/01/42		2,395		2,416,196
Coast Community College District, GO, Series B, Election 2002, (AGM), 0.00%, 08/01/30(a)		26,425		22,625,613
County of Los Angeles California, RB, Series A, 4.00%, 06/30/21		81,000		82,018,170
County of Santa Clara California, GO, Series B, Election 2008, 4.00%, 08/01/42		14,995		15,659,129
Fremont Unified School District/Alameda County California, GO, Series A, 4.00%, 08/01/46		66,330		71,615,174
Fremont Union High School District, GO 4.00%, 08/01/44		36,730		40,092,999
Series A, 4.00%, 08/01/46		9,000		10,260,540
Glendale Community College District, GO, Series A, Election 2016, 5.25%, 08/01/41		10,450		12,917,663

Security	Par (000)		Value
County/City/Special District/School District (continued)
Grossmont-Cuyamaca Community College District, GO, Series B, Election 2012, 5.00%, 08/01/44	$	30,215	$	38,172,725
Hacienda La Puente Unified School District, GO, Series A, Election 2016, 5.25%, 08/01/42		5,000		6,168,750
Imperial Irrigation District, RB, (AMBAC), 6.94%, 01/01/26		15,570		18,637,134
Los Altos Elementary School District, Refunding GO, Series A-1, Election 2014, 4.00%, 08/01/44		5,000		5,611,500
Los Angeles Community College District, GO 2.11%, 08/01/32		2,590		2,617,480
Series K, 4.00%, 08/01/36		4,125		4,733,025
Series K, Election 2008, 4.00%, 08/01/37		10,000		11,397,200
Series K, Election 2008, 4.00%, 08/01/38		20,000		22,791,200
Series K, Election 2008, 4.00%, 08/01/39		20,000		22,689,200
Los Angeles County Metropolitan Transportation Authority, RB, 4.00%, 06/01/37		1,475		1,766,018
Los Angeles County Metropolitan Transportation Authority, Refunding RB
Series A, 5.00%, 07/01/37		19,235		23,602,114
Series A, 5.00%, 07/01/44		25,885		32,035,535
Marin Healthcare District, GO, Series A, Election 2013, 5.00%, 08/01/41		21,670		26,727,561
Menifee Union School District, GO, Series A, 5.25%, 08/01/42		7,275		8,934,428
Mount San Antonio Community College District GO, Series 2018-A, Election 2018, 4.00%, 08/01/49		10,200		11,775,084
Mount San Antonio Community College District, Refunding GO, Series A, Election 2018, 5.00%, 08/01/44		11,000		13,836,240
Mountain View-Whisman School District, GO, Series B, Election 2012, 4.00%, 09/01/42		12,000		13,545,600
Orange County Local Transportation Authority, RB, 5.00%, 02/15/40		5,000		6,292,600
Palomar Community College District, GO, Series D, Election 2006, 5.25%, 08/01/45		3,000		3,714,090
Pomona Redevelopment Agency Successor Agency, Refunding TA, 3.98%, 02/01/27		4,155		4,637,437
Riverside County Public Financing Authority, RB, 5.25%, 11/01/45		11,210		13,083,303
San Diego Community College District, Refunding GO, 5.00%, 08/01/41		20,000		23,909,200
San Diego County Regional Transportation Commission, Refunding RB, Series A, 3.00%, 10/01/22(b)		27,500		28,647,025
San Diego Unified School District, GO, Series L-2, 4.00%, 07/01/39(b)		3,680		4,328,342
San Francisco Bay Area Rapid Transit District, GO
Series C-1, 3.00%, 08/01/50		12,000		12,546,120
Series A, Election 2016, 5.00%, 08/01/47		8,980		10,825,749
San Francisco Bay Area Rapid Transit District, Refunding GO, Series D, Election 2004, 4.00%, 08/01/35		5,985		6,742,222
San Francisco City & County Redevelopment Agency Successor Agency, Refunding TA
Series D, 3.13%, 08/01/28		1,150		1,230,857
Series D, 3.25%, 08/01/29		1,000		1,068,830
Series D, 3.38%, 08/01/30		1,250		1,334,988
San Francisco City & County Redevelopment Agency Successor Agency, TA, Series D, 0.00%, 08/01/23(a)(c)		1,000		903,120

1

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
County/City/Special District/School District (continued)
San Francisco City & County Redevelopment Agency Successor Agency, TA, CAB, Series D, 0.00%, 08/01/31(a)(c)	$	3,000	$	1,821,600
San Francisco City & County Redevelopment Financing Authority, TA, Series A, (BHAC-CR MBIA), 5.75%, 08/01/37		7,500		9,949,575
San Francisco Unified School District, RB, 2.00%, 12/31/21(b)		40,000		40,595,600
San Joaquin County Transportation Authority, Refunding RB, 5.00%, 03/01/41		17,955		21,497,701
San Jose Evergreen Community College District, GO, Series C, Election 2010, 4.13%, 09/01/24(d)		18,435		20,823,992
San Jose Financing Authority, RB, 5.75%, 05/01/42		2,010		2,027,467
San Jose Redevelopment Agency Successor Agency, Refunding TA, Series A-T, 3.25%, 08/01/29		8,730		9,603,262
San Jose Unified School District, GO, CAB, Series C, (NPFGC), 0.00%, 06/01/31(a)		25,000		21,053,750
San Leandro Unified School District, GO, Series A, Election 2010, 5.75%, 08/01/41		5,000		5,105,500
San Mateo County Community College District, GO, Series B, Election 2014, 5.00%, 09/01/45		32,650		40,344,299
Santa Clara County Financing Authority, RB, Series A, 4.00%, 04/01/35		6,975		8,188,650
Santa Monica Community College District, GO, Series B, Election 2008, 4.00%, 08/01/24(d)		40,015		44,927,642
Vista Joint Powers Financing Authority, Refunding RB, 5.25%, 05/01/37		15,065		17,709,058
				1,049,324,639
Education — 6.2%
California Educational Facilities Authority, RB
Series A, 3.43%, 04/01/30		1,000		1,047,830
Series A, 3.56%, 04/01/31		2,000		2,095,900
California Infrastructure & Economic Development Bank, RB(c)
Series A, 4.13%, 01/01/35		1,010		1,022,019
Series A, 5.00%, 01/01/55		2,300		2,423,349
Series A-2, 5.00%, 01/01/24		850		850,671
Series A, AMT, 0.45%, 01/01/50(e)		50,000		49,981,500
California Infrastructure & Economic Development Bank, RB, CAB(a)
0.00%, 01/01/35		2,750		1,195,892
0.00%, 01/01/60		37,500		3,298,875
California Infrastructure & Economic Development Bank, Refunding RB, Series A, 1.84%, 10/01/31		1,100		1,090,045
California Municipal Finance Authority RB(c) 5.00%, 06/15/41		925		973,664
5.00%, 06/15/51		1,385		1,431,301
California Municipal Finance Authority, RB 6.00%, 07/01/44		500		537,070
Series A, 5.50%, 08/01/34(c)		300		319,014
Series A, AMT, 4.00%, 07/15/29		6,605		7,327,983
California Municipal Finance Authority, Refunding RB 5.00%, 08/01/39		1,785		1,869,395
5.00%, 08/01/48		2,140		2,178,413
Series A, 5.00%, 11/01/39(c)		980		1,098,355
Series A, 5.00%, 11/01/49(c)		1,105		1,216,373
California Public Finance Authority, RB(c)
Series A, 5.00%, 07/01/36		385		393,778
Series A, 5.00%, 07/01/44		375		380,089

Security	Par (000)		Value
Education (continued)
California Public Finance Authority, RB(c) (continued)
Series A, 5.00%, 07/01/54	$	520	$	507,868
Series B, 5.00%, 07/01/26		265		264,263
California School Finance Authority, RB(c) 5.00%, 06/01/40		1,420		1,532,137
5.00%, 06/01/50		2,240		2,342,323
5.00%, 06/01/59		3,565		3,703,286
Series A, 5.00%, 06/01/33		525		579,989
Series A, 5.00%, 06/01/43		525		565,168
Series A, 5.00%, 06/01/49		7,105		7,582,172
Series A, 6.00%, 07/01/51		1,500		1,657,155
Series A, 5.00%, 06/01/55		1,000		1,045,140
Series A, 5.00%, 06/01/58		3,355		3,558,716
Series A, 6.00%, 06/01/59		8,925		9,704,777
Series B, 6.00%, 06/01/31		735		697,192
California State University, RB, Series D, 1.69%, 11/01/29		5,000		4,945,150
California State University, Refunding RB, Series A, 5.00%, 11/01/41		10,000		11,726,100
Hastings Campus Housing Finance Authority, RB, Series A, 5.00%, 07/01/61		15,170		16,793,190
University of California, RB
Series AV, 5.25%, 05/15/42		12,220		15,062,739
Series Q, 5.00%, 05/15/46(b)		22,320		27,865,404
University of California, RB, BAB, 6.30%, 05/15/50		3,790		5,004,960
				195,869,245
Health — 2.7%
California Health Facilities Financing Authority Refunding RB, Series A, 4.00%, 04/01/44		12,215		13,935,727
California Health Facilities Financing Authority, RB
Series A, 5.00%, 11/15/36		2,755		3,369,806
Series A, 5.00%, 11/15/40		20,220		20,861,783
Series A, 5.25%, 11/01/41		7,000		7,220,500
California Health Facilities Financing Authority, Refunding RB
Series A, 5.00%, 11/15/38		15,050		18,328,191
Series A, 4.00%, 11/15/40		5,140		5,833,848
Series A, 4.00%, 08/15/50		1,025		1,168,551
Sub-Series A-2, 4.00%, 11/01/38		4,000		4,572,280
California Statewide Communities Development Authority, RB, 5.00%, 06/01/51(c)		1,035		1,139,090
California Statewide Communities Development Authority, Refunding RB(c)
Series A, 5.00%, 06/01/36		2,900		3,172,687
Series A, 5.00%, 06/01/46		4,100		4,398,603
				84,001,066
Housing(c) — 0.2%
California Community Housing Agency, RB, M/F Housing, Series A, 5.00%, 04/01/49		2,630		2,972,216
CSCDA Community Improvement Authority, RB, M/F Housing, Series A, 5.00%, 07/01/51		4,070		4,785,506
				7,757,722
State — 2.9%
California State Public Works Board, RB
Series C, 5.00%, 11/01/44		28,895		36,086,099
Series I, 5.25%, 11/01/32		1,115		1,254,185
Series I, 5.50%, 11/01/33		2,315		2,617,941
California State Public Works Board, Refunding RB, Series C, 5.00%, 11/01/33		10,000		12,117,600

S C H E D U L E   O F   I N V E S T M E N T S 2

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
State (continued)
State of California GO, 5.00%, 10/01/39	$	11,280	$	14,330,338
State of California, Refunding GO 4.00%, 10/01/36		5,000		5,970,150
5.00%, 11/01/39		15,000		18,730,200
				91,106,513
Tobacco — 3.5%
California County Tobacco Securitization Agency, Refunding RB
5.00%, 06/01/50		1,145		1,316,658
Series A, 5.00%, 06/01/36		2,410		2,433,979
Series A, 5.00%, 06/01/47		2,595		2,620,690
Series A, 4.00%, 06/01/49		1,540		1,749,086
California County Tobacco Securitization Agency, Refunding RB, CAB, Series B-2, Subordinate, 0.00%, 06/01/55(a)		15,770		2,977,376
California Statewide Financing Authority RB, Series D, 0.00%, 06/01/55(a)(c)		16,500		862,785
Golden State Tobacco Securitization Corp., Refunding RB
Series A-1, 5.00%, 06/01/47		12,125		12,545,374
Series A-2, 5.00%, 06/01/47		55,680		57,610,426
Inland Empire Tobacco Securitization Corp., Refunding RB, 3.68%, 06/01/38		5,460		5,647,879
Silicon Valley Tobacco Securitization Authority, RB, Series D, 0.00%, 06/01/56(a)		29,500		2,748,515
Tobacco Securitization Authority of Southern California, Refunding RB, 5.00%, 06/01/48		15,670		18,797,118
				109,309,886
Transportation — 12.6%
Bay Area Toll Authority, Refunding RB, 4.00%, 04/01/34		8,075		9,387,026
Burbank-Glendale-Pasadena Airport Authority Brick Campaign, RB, Series B, 5.56%, 07/01/32		1,000		1,157,470
City of Long Beach California Harbor Revenue, RB, Series A, 5.00%, 05/15/44		10,000		12,154,000
City of Los Angeles Department of Airports, ARB
Series A, AMT, 5.00%, 05/15/40		6,615		7,615,188
Sub-Series A, AMT, 5.00%, 05/15/42		10,100		11,672,065
City of Los Angeles Department of Airports, RB
Series A, AMT, 5.00%, 05/15/42		23,725		27,891,822
Series B, AMT, 5.00%, 05/15/41		18,710		21,660,380
Series D, AMT, 5.00%, 05/15/41		8,850		10,148,472
City of Los Angeles Department of Airports, Refunding ARB, Series A, AMT, 5.00%, 05/15/46		15,550		19,325,851
City of Los Angeles Department of Airports, Refunding RB
Series A, 5.00%, 05/15/36		11,260		14,469,888
Series A, 5.00%, 05/15/38		7,230		9,210,875
Subordinate, AMT, 5.00%, 05/15/39		9,225		11,264,002
Los Angeles County Metropolitan Transportation Authority, Refunding RB, Series A, 5.00%, 07/01/42		10,000		12,157,800
Norman Y Mineta San Jose International Airport SJC, Refunding RB
Series A, AMT, 5.00%, 03/01/41		20,000		23,360,600
Series A-1, AMT, 5.75%, 03/01/34		6,720		6,736,061
Series A-1, AMT, 6.25%, 03/01/34		2,920		2,927,680

Security	Par (000)		Value
Transportation (continued)
San Francisco City & County Airport Comm-San Francisco International Airport, Refunding ARB
Series A, AMT, 5.00%, 05/01/40	$	14,000	$	15,748,180
Series A, AMT, 5.00%, 05/01/42		29,480		34,612,763
Series A, AMT, 5.00%, 05/01/44		10,125		11,282,186
Series A, AMT, 5.00%, 05/01/49		10,000		11,968,700
Series B, AMT, 5.00%, 05/01/41		23,960		27,737,533
San Francisco City & County Airport Comm-San Francisco International Airport, Refunding RB
Series 2020, AMT, 4.00%, 05/01/39		2,250		2,577,577
Series A, AMT, 5.00%, 05/01/39		5,125		5,768,854
Series A, AMT, 5.25%, 05/01/42		40,370		48,123,462
Series E, AMT, 5.00%, 05/01/38		9,025		11,027,918
San Francisco Municipal Transportation Agency, RB(b)
Series C, 4.00%, 03/01/46		18,000		20,555,100
Series C, 5.00%, 03/01/51		5,715		7,116,604
				397,658,057
Utilities — 17.2%
California Statewide Communities Development Authority Refunding RB, 1.68%, 02/01/29		1,000		981,730
City of Los Angeles California Wastewater System Revenue, RB, Series A, 5.25%, 06/01/47		20,000		24,173,200
City of Los Angeles California Wastewater System Revenue, Refunding RB
Series A, 5.00%, 06/01/43		10,000		12,170,600
Series C, 5.00%, 06/01/35		4,520		5,336,267
City of Sacramento California Water Revenue, RB, 5.00%, 09/01/42		6,465		7,853,488
City of San Francisco California Public Utilities Commission Water Revenue, Refunding RB, Series A, 4.00%, 11/01/30		19,910		23,334,719
East Bay Municipal Utility District Water System Revenue, RB, Series A, 4.00%, 06/01/45		4,885		5,568,070
East Bay Municipal Utility District Water System Revenue, Refunding RB, Series A, 5.00%, 06/01/37		7,160		8,384,861
Eastern Municipal Water District Financing Authority, RB, Series D, 5.25%, 07/01/42		18,500		22,821,970
Los Angeles Department of Water, Refunding RB
Series A, 5.00%, 07/01/41		59,070		70,420,205
Series A, 5.25%, 07/01/44		10,650		12,894,487
Metropolitan Water District of Southern California, RB
Series A, 5.00%, 07/01/40		16,105		19,013,724
Series A, 5.00%, 10/01/51		5,000		6,468,350
Metropolitan Water District of Southern California, Refunding RB 5.00%, 01/01/38		7,000		8,792,770
Series A, 5.00%, 10/01/35		5,000		5,251,100
Northern California Power Agency, RB, Series A, 7.31%, 06/01/40		2,150		3,176,926
Sacramento Municipal Utility District, RB
Series G, 5.00%, 08/15/38		22,390		28,599,643
Series G, 5.00%, 08/15/41		20,000		25,387,000
San Diego County Water Authority, Refunding RB, Series B, 5.00%, 05/01/38		20,405		24,444,986
San Diego Public Facilities Financing Authority Refunding RB
Series A, 4.00%, 08/01/39		2,515		2,975,572

3

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Utilities (continued)
San Diego Public Facilities Financing Authority Refunding RB (continued)
Series A, 4.00%, 08/01/40	$	2,000	$	2,354,680
Series A, 3.00%, 08/01/49		8,000		8,490,560
San Diego Public Facilities Financing Authority, Refunding RB
Series A, 5.00%, 05/15/36		5,000		6,050,400
Series A, 5.00%, 05/15/38		13,595		16,394,618
Series B, 5.00%, 08/01/38		16,460		19,629,538
Series A, Subordinate, 5.00%, 08/01/43		33,820		41,977,722
Series A, Subordinate, 5.25%, 08/01/47		15,180		19,037,693
San Francisco City & County Public Utilities Commission Wastewater Revenue, Refunding RB, Series B, 4.00%, 10/01/42		17,010		17,917,654
San Mateo Foster City Public Financing Authority, RB, 4.00%, 08/01/44		7,250		8,373,315
Southern California Public Power Authority, Refunding RB, 5.00%, 07/01/30		41,400		46,569,618
State of California Department of Water Resources RB, Series BB, 5.00%, 12/01/35		2,000		2,666,560
State of California Department of Water Resources, Refunding RB
Series AW, 4.00%, 12/01/34		24,000		27,808,800
Series BC, 1.32%, 12/01/28		4,000		3,951,440
				539,272,266
Total Municipal Bonds in California				2,475,677,890
Connecticut — 0.2%
Corporate — 0.2%
Mashantucket Western Pequot Tribe, (6.35% Cash or 1.00% PIK), 7.35%, 07/01/26(f)(g)(h)		36,909		5,536,365
Illinois — 1.3%
County/City/Special District/School District — 1.3%
Chicago Board of Education, GO, 6.32%, 11/01/29		3,650		4,408,543
Chicago Board of Education, GO, BAB 6.04%, 12/01/29		7,590		8,863,830
6.14%, 12/01/39		13,850		16,489,117
6.52%, 12/01/40		8,075		9,979,812
Total Municipal Bonds in Illinois				39,741,302
Puerto Rico — 8.7%
State — 4.9%
Commonwealth of Puerto Rico, GO(f)(g)
Series A, 5.25%, 07/01/22		940		817,985
Series A, 5.25%, 07/01/26		330		287,165
Series A, 5.13%, 07/01/31		3,340		2,906,458
Series A, 5.38%, 07/01/33		1,025		891,952
Series A, 6.00%, 07/01/38		1,630		1,422,423
Commonwealth of Puerto Rico, Refunding GO(f)(g) 5.00%, 07/01/18		470		409,488
Series A, 5.50%, 07/01/18		1,025		893,031
Series A, 5.50%, 07/01/32		1,170		1,018,131
Series A, 6.00%, 07/01/34		955		803,527
Series A, 8.00%, 07/01/35		27,405		21,207,277
Series A, 5.50%, 07/01/39		8,805		7,192,778
Series A, 5.00%, 07/01/41		10,546		8,193,113
Series B, 6.00%, 07/01/39		3,970		3,464,428
Series C, 6.00%, 07/01/39		470		410,146

Security	Par (000)		Value
State (continued)
Commonwealth of Puerto Rico, Refunding GO(f)(g) (continued) Series D, 5.75%, 07/01/41	$	1,110	$	921,038
Puerto Rico Public Buildings Authority, Refunding RB(f)(g)
Series F, (GTD), 5.25%, 07/01/24		500		481,106
Series M-2, (GTD), 10.00%, 07/01/34		1,045		877,800
Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, RB
Series A-1, Restructured, 4.75%, 07/01/53		31,268		33,980,812
Series A-1, Restructured, 5.00%, 07/01/58		11,287		12,438,725
Series A-2, Restructured, 4.33%, 07/01/40		11,004		11,709,808
Series A-2, Restructured, 4.54%, 07/01/53		114		122,469
Series A-2, Restructured, 4.78%, 07/01/58		12,102		13,289,569
Puerto Rico Sales Tax Financing Corp. Sales Tax Revenue, RB, CAB(a)
Series A-1, Restructured, 0.00%, 07/01/29		1,117		915,080
Series A-1, Restructured, 0.00%, 07/01/31		1,330		1,007,754
Series A-1, Restructured, 0.00%, 07/01/33		1,909		1,340,710
Series A-1, Restructured, 0.00%, 07/01/46		86,260		26,394,697
Series B-1, Restructured, 0.00%, 07/01/46		5,761		1,759,928
				155,157,398
Tobacco(a) — 0.5%
Children’s Trust Fund, RB
Series A, 0.00%, 05/15/57		150,000		10,254,000
Series B, 0.00%, 05/15/57		97,000		5,145,850
				15,399,850
Utilities — 3.3%
Puerto Rico Electric Power Authority,, 3rd Series, 5.40%, 01/01/21(e)(f)(g)		593		536,675
Puerto Rico Electric Power Authority, RB
Series A, 5.00%, 07/01/29(f)(g)		4,130		3,734,875
Series A, 7.00%, 07/01/33(f)(g)		2,230		2,079,475
Series A, 6.75%, 07/01/36(f)(g)		7,630		7,114,975
Series A, 5.00%, 07/01/42(f)(g)		8,830		7,985,216
Series A, 7.00%, 07/01/43(f)(g)		955		890,538
Series A-3, 10.00%, 07/01/19(f)(g)		2,137		2,052,047
Series B-3, 10.00%, 07/01/19(f)(g)		2,137		2,052,047
Series C-1, 5.40%, 01/01/18(f)(g)		5,870		5,308,358
Series C-2, 5.40%, 07/01/18(f)(g)		5,871		5,309,217
Series C-4, 5.40%, 07/01/20(f)(g)		593		536,675
Series CCC, 5.25%, 07/01/26(f)(g)		1,680		1,519,271
Series CCC, 5.25%, 07/01/28(f)(g)		955		863,633
Series D-4, 7.50%, 07/01/20		1,638		1,527,435
Series TT, 5.00%, 07/01/25(f)(g)		480		434,077
Series TT, 5.00%, 07/01/26(f)(g)		1,285		1,162,062
Series TT, 5.00%, 07/01/32(f)(g)		1,075		972,153
Series WW, 5.50%, 07/01/19(f)(g)		2,470		2,233,690
Series WW, 5.38%, 07/01/22(f)(g)		1,250		1,130,410
Series WW, 5.38%, 07/01/24(f)(g)		875		791,287
Series WW, 5.25%, 07/01/33(f)(g)		885		800,330
Series WW, 5.50%, 07/01/38(f)(g)		1,170		1,058,064
Series WW, 5.50%, 07/01/49(f)(g)		935		845,547
Series XX, 5.25%, 07/01/27(f)(g)		645		583,292
Series XX, 5.25%, 07/01/35(f)(g)		400		361,731
Series XX, 5.75%, 07/01/36(f)(g)		555		501,902
Series XX, 5.25%, 07/01/40(f)(g)		11,490		10,390,729

S C H E D U L E   O F   I N V E S T M E N T S 4

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund (Percentages shown are based on Net Assets)

Security	Par (000)		Value
Utilities (continued)
Puerto Rico Electric Power Authority, Refunding RB(f)(g)
Series AAA, 5.25%, 07/01/22	$	2,150	$	1,944,305
Series AAA, 5.25%, 07/01/24		480		434,077
Series AAA, 5.25%, 07/01/26		1,840		1,663,964
Series AAA, 5.25%, 07/01/27		6,540		5,914,305
Series AAA, 5.25%, 07/01/28		4,690		4,241,298
Series AAA, 5.25%, 07/01/29		530		479,294
Series BBB, 5.40%, 07/01/28		2,805		2,536,640
Series UU, 1.00%, 07/01/19(e)		355		289,325
Series UU, 1.16%, 07/01/19(e)		395		321,925
Series UU, 1.00%, 07/01/20(e)		3,175		2,651,795
Series UU, 0.86%, 07/01/31(e)		3,765		3,144,569
Series ZZ, 5.25%, 07/01/19		2,945		2,663,246
Series ZZ, 5.25%, 07/01/21		3,590		3,246,538
Series ZZ, 5.25%, 07/01/24		1,990		1,799,613
Series ZZ, 5.25%, 07/01/26		4,335		3,920,262
Series ZZ, 5.00%, 07/01/28		990		895,285
Series ZZ, 5.00%, 07/01/49		925		836,503
Puerto Rico Electric Power Authority, Refunding RB, BAB, Series YY, 6.13%, 07/01/40(f)(g)		4,060		3,671,572
				103,430,227
Total Municipal Bonds in Puerto Rico				273,987,475
Total Municipal Bonds — 88.9% (Cost: $2,636,018,474)				2,794,943,032
Municipal Bonds Transferred to Tender Option Bond Trusts(i)
California — 10.9%
County/City/Special District/School District — 2.4%
Irvine Ranch Water District, COP, 5.00%, 03/01/46		19,330		22,943,164
Ohlone Community College District, GO, Series B, 4.00%, 08/01/44		47,250		51,498,247
				74,441,411
Education — 3.8%
California State University, Refunding RB, Series A, 5.00%, 11/01/43		35,250		42,993,367
University of California, RB, Series M, 5.00%, 05/15/42		20,000		23,876,400
University of California, Refunding RB, Series AZ, 5.00%, 05/15/43		41,740		51,348,131
				118,217,898
State — 0.7%
State of California, Refunding GO, 5.25%, 10/01/39		18,150		21,711,756
Utilities — 4.0%
East Bay Municipal Utility District Water System Revenue, RB, Series A, 5.00%, 06/01/42		27,045		33,003,266

Security	Par (000)		Value
Utilities (continued)
Eastern Municipal Water District Financing Authority, RB, Series D, 5.00%, 07/01/47	$	36,105	$	43,605,100
San Francisco City & County Public Utilities Commission Wastewater Revenue, RB, Series B, 5.00%, 10/01/43		41,405		50,442,878
				127,051,244
Total Municipal Bonds in California				341,422,309
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 10.9% (Cost: $314,907,492)				341,422,309
Total Long-Term Investments — 100.0% (Cost: $2,959,375,975)				3,144,445,922
	Shares
Short-Term Securities
Money Market Funds — 6.1%
BlackRock Liquidity Funds California Money Fund, Institutional Class, 0.01%(j)(k)		191,964,739		192,079,918
Total Short-Term Securities — 6.1% (Cost: $191,968,796)				192,079,918
Total Investments — 106.1% (Cost: $3,151,344,771)				3,336,525,840
Liabilities in Excess of Other Assets — (1.5)%			(48,912,375)
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (4.6)%				(143,185,977	)
Net Assets — 100.0%			$	3,144,427,488

^(a)  Zero-coupon bond.

^(b)  When-issued security.

^(c)  Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933, as amended. These securities may be resold in transactions exempt from registration to qualified institutional investors.

^(d)  U.S. Government securities held in escrow, are used to pay interest on this security as well as to retire the bond in full at the date indicated, typically at a premium to par.

^(e)  Variable rate security. Interest rate resets periodically. The rate shown is the effective interest rate as of period end. Security description also includes the reference rate and spread if published and available.

^(f)  Issuer filed for bankruptcy and/or is in default.

^(g)  Non-income producing security.

^(h)  Payment-in-kind security which may pay interest/dividends in additional par/shares and/or in cash. Rates shown are the current rate and possible payment rates.

⁽ⁱ⁾  Represent bonds transferred to a TOB Trust in exchange of cash and residual certificates received by the Fund. These bonds serve as collateral in a secured borrowing.

^(j)  Affiliate of the Fund.

^(k)  Annualized 7-day yield as of period end.

For Fund compliance purposes, the Fund’s sector classifications refer to one or more of the sector sub-classifications used by one or more widely recognized market indexes or rating group indexes, and/or as defined by the investment adviser. These definitions may not apply for purposes of this report, which may combine such sector sub-classifications for reporting ease.

5

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund     

Affiliates

Investments in issuers considered to be affiliate(s) of the Fund during the period ended February 28, 2021 for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:

Affiliated Issuer	Value at 05/31/20		Purchases at Cost		Proceeds from Sales			Net Realized Gain (Loss)		Change in Unrealized Appreciation (Depreciation)		Value at 02/28/21		Shares Held at 02/28/21		Income		Capital Gain Distributions from Underlying Funds
BlackRock Liquidity Funds California Money Fund, Institutional Class	$	322,516,448	$	—	$	(130,513,394	)(a)	$	7,928	$	68,936	$	192,079,918		191,964,739	$	14,333	$	—

^(a)  Represents net amount purchased (sold).

Derivative Financial Instruments Outstanding as of Period End

Futures Contracts

Description	Number of Contracts		Expiration Date		Notional Amount (000)		Value/ Unrealized Appreciation (Depreciation)
Short Contracts
U.S. 10 Year Note		2,551		06/21/21	$	339,921	$	2,442,451
U.S. Long Bond		842		06/21/21		135,457		403,913
							$	2,846,364

Fair Value Hierarchy as of Period End

Various inputs are used in determining the fair value of financial instruments. These inputs to valuation techniques are categorized into a fair value hierarchy consisting of three broad levels for financial reporting purposes as follows:

• Level 1 – Unadjusted price quotations in active markets/exchanges for identical assets or liabilities that the Fund has the ability to access;

• 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, prepayment speeds, loss severities, credit risks and default rates) or other market–corroborated inputs); and

• Level 3 – Unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the BlackRock Global Valuation Methodologies Committee’s (the “Global Valuation Committee’s”) assumptions used in determining the fair value of financial instruments).

The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). Accordingly, the degree of judgment exercised in determining fair value is greatest for instruments categorized in Level 3. The inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the fair value hierarchy classification is determined based on the lowest level input that is significant to the fair value measurement in its entirety. Investments classified within Level 3 have significant unobservable inputs used by the Global Valuation Committee in determining the price for Fair Valued Investments. Level 3 investments include equity or debt issued by privately held companies or funds. There may not be a secondary market, and/or there are a limited number of investors. The categorization of a value determined for financial instruments is based on the pricing transparency of the financial instruments and is not necessarily an indication of the risks associated with investing in those securities. For information about the Fund’s policy regarding valuation of financial instruments, refer to its most recent financial statements.

The following table summarizes the Fund’s investments and derivative financial instruments categorized in the disclosure hierarchy. The breakdown of the Fund’s investments into major categories is disclosed in the Schedule of Investments above.

	Level 1		Level 2		Level 3		Total
Assets
Investments
Long-Term Investments
Corporate Bonds	$	—	$	8,080,581	$	—	$	8,080,581
Municipal Bonds		—		2,794,943,032		—		2,794,943,032
Municipal Bonds Transferred to Tender Option Bond Trusts		—		341,422,309		—		341,422,309

S C H E D U L E   O F   I N V E S T M E N T S 6

Schedule of Investments (unaudited) (continued) February 28, 2021 BlackRock California Municipal Opportunities Fund     

Fair Value Hierarchy as of Period End (continued)

	Level 1		Level 2		Level 3		Total
Short-Term Securities
Money Market Funds	$	192,079,918	$	—	$	—	$	192,079,918
	$	192,079,918	$	3,144,445,922	$	—	$	3,336,525,840
Derivative Financial Instruments(a)
Assets
Interest Rate Contracts	$	2,846,364	$	—	$	—	$	2,846,364

^(a)  Derivative financial instruments are futures contracts. Futures contracts are valued at the unrealized appreciation (depreciation) on the instrument.

The Fund may hold assets and/or liabilities in which the fair value approximates the carrying amount for financial statement purposes. As of period end, TOB Trust Certificates of $143,144,977 are categorized as Level 2 within the fair value hierarchy.

Portfolio Abbreviation

AGM	Assured Guaranty Municipal Corp.
AMBAC	AMBAC Assurance Corp.
AMT	Alternative Minimum Tax
ARB	Airport Revenue Bonds
BAB	Build America Bond
CAB	Capital Appreciation Bonds
COP	Certificates of Participation
CR	Custodian Receipt
GO	General Obligation Bonds
GOL	General Obligation Ltd.
GTD	GTD Guaranteed
M/F	Multi-Family
NPFGC	National Public Finance Guarantee Corp.
PIK	Payment-in-Kind
RB	Revenue Bond
SAB	Special Assessment Bonds
ST	Special Tax
TA	Tax Allocation

7