<TABLE> <S> <C>
<ARTICLE> 6
<LEGEND>
this schedule contains summary financial information extracted from mason street
funds, inc. aggressive growth stock fund, 09/30/00 financial statements class b.
</LEGEND>
<CIK> 0001023744
<NAME> MASON STREET FUNDS, INC.
<SERIES>
<NUMBER> 052
<NAME> AGGRESSIVE GROWTH STOCK FUND CLASS B
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> MAR-31-2001
<PERIOD-START> APR-01-2000
<PERIOD-END> SEP-30-2000
<INVESTMENTS-AT-COST> 68,248,255
<INVESTMENTS-AT-VALUE> 105,158,647
<RECEIVABLES> 412,434
<ASSETS-OTHER> 149,393
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 105,720,474
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 330,270
<TOTAL-LIABILITIES> 330,270
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 52,393,012
<SHARES-COMMON-STOCK> 549,497
<SHARES-COMMON-PRIOR> 498,718
<ACCUMULATED-NII-CURRENT> (391,327)
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 16,478,127
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 36,910,392
<NET-ASSETS> 105,390,204
<DIVIDEND-INCOME> 39,703
<INTEREST-INCOME> 235,248
<OTHER-INCOME> 0
<EXPENSES-NET> (666,278)
<NET-INVESTMENT-INCOME> (391,327)
<REALIZED-GAINS-CURRENT> 6,388,353
<APPREC-INCREASE-CURRENT> 394,550
<NET-CHANGE-FROM-OPS> 6,391,576
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 0
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 75,791
<NUMBER-OF-SHARES-REDEEMED> 25,012
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> 9,140,999
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 10,088,621
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 363,407
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 718,289
<AVERAGE-NET-ASSETS> 11,800,731
<PER-SHARE-NAV-BEGIN> 22.86
<PER-SHARE-NII> (.26)
<PER-SHARE-GAIN-APPREC> 1.63
<PER-SHARE-DIVIDEND> 0.00
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 24.23
<EXPENSE-RATIO> 1.95
</TABLE>
