<PAGE> PAGE 1
000 A000000 02/29/96
000 C000000 0000055626
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 U
001 A000000 KEYSTONE MID-CAP GROWTH FUND (S-3)
001 B000000 811-100
001 C000000 6173383200
002 A000000 200 BERKELEY STREET
002 B000000 BOSTON
002 C000000 MA
002 D010000 02116
003 000000 N
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007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
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008 A000001 KEYSTONE INVESTMENT MANAGEMENT CO.
008 B000001 A
008 C000001 801-8327
008 D010001 BOSTON
008 D020001 MA
008 D030001 02116
008 D040001 5034
010 A000001 KEYSTONE INVESTMENTS, INC.
010 C010001 BOSTON
010 C020001 MA
010 C030001 02116
010 C040001 5034
011 A000001 KEYSTONE INVESTMENT DISTRIBUTORS CO.
011 B000001 8-395
011 C010001 BOSTON
011 C020001 MA
011 C030001 02116
011 C040001 5034
012 A000001 KEYSTONE INVESTORS RESOURCE CENTER
<PAGE> PAGE 2
012 B000001 84-1571
012 C010001 CAMBRIDGE
012 C020001 MA
012 C030001 02142
013 A000001 KPMG PEAT MARWICK LLP
013 B010001 BOSTON
013 B020001 MA
013 B030001 02110
015 A000001 STATE STREET BANK & TRUST CO.
015 B000001 C
015 C010001 QUINCY
015 C020001 MA
015 C030001 02171
015 E010001 X
019 B000000 0
020 A000001 NEWBRIDGE SECURITIES
020 C000001 78
020 A000002 MERRILL LUNCH PIERCE FENNER & SMITH
020 B000002 13-5674085
020 C000002 45
020 A000003 EXECUTION SERVICES, INC.
020 C000003 38
020 A000004 BEAR, STEARNS SECURITIES
020 C000004 29
020 A000005 CS FIRST BOSTON CORP
020 C000005 28
020 A000006 GOLDMAN SACHS
020 C000006 26
020 A000007 COWEN & CO.
020 C000007 25
020 A000008 DONALDSON, LUFKIN & JENRE
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020 A000009 PAINE WEBER CORP.
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020 A000010 GEORGE KEMBLE
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022 A000001 NEWBRIDGE SEC
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<PAGE> PAGE 3
022 A000005 SMITH BARNEY, INC.
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022 C000005 8495
022 D000005 4150
022 A000006 CS FIRST BOSTON CORP
022 C000006 6572
022 D000006 5670
022 A000007 GEORGE KEMBLE
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022 A000008 EXECUTION SERVICES, INC.
022 C000008 846
022 D000008 10456
022 A000009 PAINE WEBBER, INC.
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022 C000009 1005
022 D000009 9774
022 A000010 COWEN & CO
022 C000010 5573
022 D000010 4361
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<PAGE> PAGE 4
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<PAGE> PAGE 5
070 F010000 Y
070 F020000 N
070 G010000 Y
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070 H010000 Y
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<PAGE> PAGE 6
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<PAGE> PAGE 7
077 C000000 N
077 D000000 N
077 E000000 N
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077 Q010000 Y
077 Q020000 N
077 Q030000 N
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080 A000000 ICI MUTUAL INSURANCE
080 B000000 FREDERICK JONES
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SIGNATURE J. KEVIN KENELY
TITLE TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM ACCOUNTING
RECORDS AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH ACCOUNTING
RECORDS.
</LEGEND>
<SERIES>
<NUMBER> 101
<NAME> KEYSTONE MID-CAP GROWTH FUND (S-3) CLASS A
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> AUG-31-1996
<PERIOD-START> SEP-01-1995
<PERIOD-END> FEB-29-1996
<INVESTMENTS-AT-COST> 264,829,882
<INVESTMENTS-AT-VALUE> 300,870,425
<RECEIVABLES> 6,175,783
<ASSETS-OTHER> 26,360
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 307,072,568
<PAYABLE-FOR-SECURITIES> 3,350,284
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 65,767
<TOTAL-LIABILITIES> 3,416,051
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 245,616,100
<SHARES-COMMON-STOCK> 33,711,744
<SHARES-COMMON-PRIOR> 29,928,715
<ACCUMULATED-NII-CURRENT> 12,659,040
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 9,340,851
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 36,040,526
<NET-ASSETS> 303,656,517
<DIVIDEND-INCOME> 949,877
<INTEREST-INCOME> 431,516
<OTHER-INCOME> 0
<EXPENSES-NET> (2,708,071)
<NET-INVESTMENT-INCOME> (1,326,678)
<REALIZED-GAINS-CURRENT> 28,448,738
<APPREC-INCREASE-CURRENT> (4,150,600)
<NET-CHANGE-FROM-OPS> 22,971,460
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> (27,721,799)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3,464,861
<NUMBER-OF-SHARES-REDEEMED> (2,628,177)
<SHARES-REINVESTED> 2,946,345
<NET-CHANGE-IN-ASSETS> 27,622,505
<ACCUMULATED-NII-PRIOR> 13,985,718
<ACCUMULATED-GAINS-PRIOR> 8,613,912
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> (933,197)
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> (2,708,071)
<AVERAGE-NET-ASSETS> 287,259,333
<PER-SHARE-NAV-BEGIN> 9.22
<PER-SHARE-NII> (0.09)
<PER-SHARE-GAIN-APPREC> 0.80
<PER-SHARE-DIVIDEND> 0.00
<PER-SHARE-DISTRIBUTIONS> (0.92)
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<PER-SHARE-NAV-END> 9.01
<EXPENSE-RATIO> 1.91
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
