<PAGE> PAGE 1
000 A000000 01/31/2000
000 C000000 0000837441
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 A
001 A000000 OPPENHEIMER CALIFORNIA MUNICIPAL FUND
001 B000000 811-5586
001 C000000 2123230200
002 A000000 TWO WORLD TRADE CENTER
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10048
002 D020000 0203
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 OPPENHEIMERFUNDS, INC.
008 B000001 A
008 C000001 801-8253
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10048
008 D040001 0203
011 A000001 OPPENHEIMERFUNDS DISTRIBUTOR, INC.
011 B000001 8-22992
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10048
011 C040001 0203
012 A000001 OPPENHEIMERFUNDS SERVICES
012 B000001 84-1562
012 C010001 ENGLEWOOD
012 C020001 CO
012 C030001 80112
<PAGE> PAGE 2
012 C040001 3924
013 A000001 KPMG LLP
013 B010001 DENVER
013 B020001 CO
013 B030001 80202
015 A000001 CITIBANK, N.A.
015 B000001 C
015 C010001 NEW YORK
015 C020001 NY
015 C030001 10154
015 E010001 X
018 000000 Y
019 A000000 Y
019 B000000 51
019 C000000 OPPENHEIMR
020 A000001 R.J. O'BRIEN
020 B000001 36-3233364
020 C000001 23
020 A000002 MERRILL LYNCH
020 B000002 13-5674085
020 C000002 5
020 A000003 SALMN SMITH BARNEY/CITIGROUP
020 B000003 13-2771536
020 C000003 2
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 30
022 A000001 SALOMON SMITH BARNEY/CITIGROUP
022 B000001 13-2771536
022 C000001 24711
022 D000001 39095
022 A000002 MORGAN STANLEY
022 B000002 13-2655998
022 C000002 13129
022 D000002 32181
022 A000003 MORGAN GUARANTY TRUST CO
022 B000003 13-5123346
022 C000003 19800
022 D000003 13200
022 A000004 BEAR STEARNS
022 B000004 13-3299429
022 C000004 8700
022 D000004 17109
022 A000005 PAINE WEBBER INC
022 B000005 13-2638166
022 C000005 13358
<PAGE> PAGE 3
022 D000005 6421
022 A000006 SUTRO & CO., INC.
022 B000006 94-1704902
022 C000006 8842
022 D000006 10336
022 A000007 LEHMAN BROTHERS
022 B000007 13-2518466
022 C000007 11796
022 D000007 6549
022 A000008 SIMON (WILLIAM E) & SONS MUNICIPAL SEC
022 B000008 22-3017217
022 C000008 8404
022 D000008 9791
022 A000009 STONE AND YOUNGBERG
022 B000009 94-1052545
022 C000009 10644
022 D000009 6037
022 A000010 MERRILL LYNCH
022 B000010 13-5674085
022 C000010 7500
022 D000010 4640
023 C000000 162511
023 D000000 181495
024 000000 N
025 D000001 0
025 D000002 0
025 D000003 0
025 D000004 0
025 D000005 0
025 D000006 0
025 D000007 0
025 D000008 0
026 A000000 Y
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
028 A010000 7547
028 A020000 1095
028 A030000 0
028 A040000 9558
028 B010000 6710
028 B020000 1102
028 B030000 0
028 B040000 9630
028 C010000 5527
<PAGE> PAGE 4
028 C020000 1105
028 C030000 0
028 C040000 12322
028 D010000 4465
028 D020000 1090
028 D030000 0
028 D040000 7366
028 E010000 4877
028 E020000 1108
028 E030000 0
028 E040000 17039
028 F010000 3464
028 F020000 1088
028 F030000 0
028 F040000 15663
028 G010000 32590
028 G020000 6588
028 G030000 0
028 G040000 71578
028 H000000 17982
029 000000 Y
030 A000000 227
030 B000000 4.75
030 C000000 0.00
031 A000000 53
031 B000000 0
032 000000 174
033 000000 0
034 000000 Y
035 000000 257
036 A000000 N
036 B000000 0
037 000000 N
038 000000 0
039 000000 N
040 000000 Y
041 000000 Y
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 100
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 1060
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.000
<PAGE> PAGE 5
048 A010000 200000
048 A020000 0.600
048 B010000 100000
048 B020000 0.550
048 C010000 200000
048 C020000 0.500
048 D010000 250000
048 D020000 0.450
048 E010000 250000
048 E020000 0.400
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 1000000
048 K020000 0.350
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 Y
053 B000000 Y
054 A000000 Y
054 B000000 Y
054 C000000 Y
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 Y
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 Y
054 M000000 Y
054 N000000 N
054 O000000 Y
055 A000000 N
055 B000000 N
056 000000 N
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 N
060 B000000 N
<PAGE> PAGE 6
061 000000 25
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 0.0
062 E000000 0.8
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 98.3
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 0
063 B000000 8.8
064 A000000 Y
064 B000000 N
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 N
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 Y
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 Y
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 N
070 J020000 N
070 K010000 N
070 K020000 N
070 L010000 N
<PAGE> PAGE 7
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 N
070 O020000 N
070 P010000 Y
070 P020000 Y
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 107857
071 B000000 145553
071 C000000 427664
071 D000000 25
072 A000000 6
072 B000000 13593
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 1223
072 G000000 0
072 H000000 0
072 I000000 116
072 J000000 27
072 K000000 15
072 L000000 31
072 M000000 15
072 N000000 0
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 10
072 S000000 3
072 T000000 1060
072 U000000 0
072 V000000 0
072 W000000 4
072 X000000 2504
072 Y000000 11
072 Z000000 11100
072AA000000 1606
072BB000000 14615
072CC010000 0
072CC020000 25860
072DD010000 7884
072DD020000 2727
072EE000000 0
073 A010000 0.2658
<PAGE> PAGE 8
073 A020000 0.2271
073 B000000 0.0000
073 C000000 0.0000
074 A000000 1769
074 B000000 0
074 C000000 3200
074 D000000 388048
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 0
074 L000000 6680
074 M000000 10
074 N000000 399707
074 O000000 2003
074 P000000 183
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 2661
074 S000000 0
074 T000000 394860
074 U010000 28030
074 U020000 11339
074 V010000 9.67
074 V020000 9.68
074 W000000 0.0000
074 X000000 7696
074 Y000000 0
075 A000000 0
075 B000000 435210
076 000000 0.00
077 A000000 N
078 000000 N
080 A000000 ICI MUTUAL INSURANCE CO.
080 C000000 92000
081 A000000 Y
081 B000000 96
082 A000000 N
082 B000000 0
083 A000000 N
083 B000000 0
084 A000000 N
084 B000000 0
085 A000000 Y
085 B000000 N
086 A010000 0
<PAGE> PAGE 9
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
SIGNATURE BRIAN W. WIXTED
TITLE TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 837441
<NAME> OPPENHEIMER CALIFORNIA MUNICIPAL FUND-A
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-START> AUG-01-1999
<PERIOD-END> JAN-31-2000
<INVESTMENTS-AT-COST> 405,127,975
<INVESTMENTS-AT-VALUE> 391,248,398
<RECEIVABLES> 6,679,506
<ASSETS-OTHER> 10,249
<OTHER-ITEMS-ASSETS> 1,768,437
<TOTAL-ASSETS> 399,706,590
<PAYABLE-FOR-SECURITIES> 2,003,396
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,843,068
<TOTAL-LIABILITIES> 4,846,464
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 423,162,561
<SHARES-COMMON-STOCK> 28,029,768
<SHARES-COMMON-PRIOR> 29,941,203
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 950,895
<ACCUMULATED-NET-GAINS> (13,657,121)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (13,694,419)
<NET-ASSETS> 271,115,987
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 13,592,960
<OTHER-INCOME> 0
<EXPENSES-NET> 2,493,019
<NET-INVESTMENT-INCOME> 11,099,941
<REALIZED-GAINS-CURRENT> (13,008,721)
<APPREC-INCREASE-CURRENT> (25,859,618)
<NET-CHANGE-FROM-OPS> (27,768,398)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 7,884,363
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2,265,606
<NUMBER-OF-SHARES-REDEEMED> 4,637,740
<SHARES-REINVESTED> 460,699
<NET-CHANGE-IN-ASSETS> (71,129,518)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (648,400)
<OVERDISTRIB-NII-PRIOR> 1,088,872
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,223,433
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,504,329
<AVERAGE-NET-ASSETS> 297,257,000
<PER-SHARE-NAV-BEGIN> 10.57
<PER-SHARE-NII> 0.27
<PER-SHARE-GAIN-APPREC> (0.90)
<PER-SHARE-DIVIDEND> 0.27
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 9.67
<EXPENSE-RATIO> 0.90
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0.00
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 837441
<NAME> OPPENHEIMER CALIFORNIA MUNICIPAL FUND-B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-START> AUG-01-1999
<PERIOD-END> JAN-31-2000
<INVESTMENTS-AT-COST> 405,127,975
<INVESTMENTS-AT-VALUE> 391,248,398
<RECEIVABLES> 6,679,506
<ASSETS-OTHER> 10,249
<OTHER-ITEMS-ASSETS> 1,768,437
<TOTAL-ASSETS> 399,706,590
<PAYABLE-FOR-SECURITIES> 2,003,396
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,843,068
<TOTAL-LIABILITIES> 4,846,464
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 423,162,561
<SHARES-COMMON-STOCK> 11,338,844
<SHARES-COMMON-PRIOR> 12,560,331
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 950,895
<ACCUMULATED-NET-GAINS> (13,657,121)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (13,694,419)
<NET-ASSETS> 109,713,187
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 13,592,960
<OTHER-INCOME> 0
<EXPENSES-NET> 2,493,019
<NET-INVESTMENT-INCOME> 11,099,941
<REALIZED-GAINS-CURRENT> (13,008,721)
<APPREC-INCREASE-CURRENT> (25,859,618)
<NET-CHANGE-FROM-OPS> (27,768,398)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 2,726,647
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 726,465
<NUMBER-OF-SHARES-REDEEMED> 2,115,668
<SHARES-REINVESTED> 167,716
<NET-CHANGE-IN-ASSETS> (71,129,518)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (648,400)
<OVERDISTRIB-NII-PRIOR> 1,088,872
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,223,433
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,504,329
<AVERAGE-NET-ASSETS> 122,265,000
<PER-SHARE-NAV-BEGIN> 10.57
<PER-SHARE-NII> 0.23
<PER-SHARE-GAIN-APPREC> (0.89)
<PER-SHARE-DIVIDEND> 0.23
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 9.68
<EXPENSE-RATIO> 1.66
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0.00
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 837441
<NAME> OPPENHEIMER CALIFORNIA MUNICIPAL FUND-C
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUL-31-2000
<PERIOD-START> AUG-01-1999
<PERIOD-END> JAN-31-2000
<INVESTMENTS-AT-COST> 405,127,975
<INVESTMENTS-AT-VALUE> 391,248,398
<RECEIVABLES> 6,679,506
<ASSETS-OTHER> 10,249
<OTHER-ITEMS-ASSETS> 1,768,437
<TOTAL-ASSETS> 399,706,590
<PAYABLE-FOR-SECURITIES> 2,003,396
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,843,068
<TOTAL-LIABILITIES> 4,846,464
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 423,162,561
<SHARES-COMMON-STOCK> 1,452,580
<SHARES-COMMON-PRIOR> 1,598,190
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 950,895
<ACCUMULATED-NET-GAINS> (13,657,121)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> (13,694,419)
<NET-ASSETS> 14,030,952
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 13,592,960
<OTHER-INCOME> 0
<EXPENSES-NET> 2,493,019
<NET-INVESTMENT-INCOME> 11,099,941
<REALIZED-GAINS-CURRENT> (13,008,721)
<APPREC-INCREASE-CURRENT> (25,859,618)
<NET-CHANGE-FROM-OPS> (27,768,398)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 350,954
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 218,864
<NUMBER-OF-SHARES-REDEEMED> 386,780
<SHARES-REINVESTED> 22,306
<NET-CHANGE-IN-ASSETS> (71,129,518)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (648,400)
<OVERDISTRIB-NII-PRIOR> 1,088,872
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,223,433
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 2,504,329
<AVERAGE-NET-ASSETS> 15,688,000
<PER-SHARE-NAV-BEGIN> 10.55
<PER-SHARE-NII> 0.23
<PER-SHARE-GAIN-APPREC> (0.89)
<PER-SHARE-DIVIDEND> 0.23
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 9.66
<EXPENSE-RATIO> 1.66
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0.00
</TABLE>