<TABLE> <S> <C>

<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE JOHN
HANCOCK VARIABLE SERIES TRUST I SEMIANNUAL REPORT DATED JUNE 30,1999 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
   <NUMBER> 10
   <NAME> SMALL CAP GROWTH
<MULTIPLIER> 1000

<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               JUN-30-1999
<INVESTMENTS-AT-COST>                           68,069
<INVESTMENTS-AT-VALUE>                          93,910
<RECEIVABLES>                                      444
<ASSETS-OTHER>                                       0
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                                  94,357
<PAYABLE-FOR-SECURITIES>                         1,414
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                           35
<TOTAL-LIABILITIES>                              1,449
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                        64,521
<SHARES-COMMON-STOCK>                            6,248
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                        (307)
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                          4,902
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                        23,792
<NET-ASSETS>                                    92,908
<DIVIDEND-INCOME>                                   24
<INTEREST-INCOME>                                   45
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                     380
<NET-INVESTMENT-INCOME>                          (311)
<REALIZED-GAINS-CURRENT>                         4,902
<APPREC-INCREASE-CURRENT>                        6,913
<NET-CHANGE-FROM-OPS>                           11,504
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                            0
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                          1,349
<NUMBER-OF-SHARES-REDEEMED>                      (864)
<SHARES-REINVESTED>                                  0
<NET-CHANGE-IN-ASSETS>                          18,059
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                              301
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                    380
<AVERAGE-NET-ASSETS>                                 0
<PER-SHARE-NAV-BEGIN>                            12.99
<PER-SHARE-NII>                                  (.05)
<PER-SHARE-GAIN-APPREC>                           1.93
<PER-SHARE-DIVIDEND>                                 0
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              14.87
<EXPENSE-RATIO>                                    .94


</TABLE>