<TABLE> <S> <C>

<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE JOHN
HANCOCK VARIABLE SERIES TRUST I ANNUAL REPORT DATED DECEMBER 31, 1998 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>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1998
<PERIOD-START>                             JAN-01-1998
<PERIOD-END>                               DEC-31-1998
<INVESTMENTS-AT-COST>                           55,256
<INVESTMENTS-AT-VALUE>                          74,839
<RECEIVABLES>                                    2,695
<ASSETS-OTHER>                                      46
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                                  77,580
<PAYABLE-FOR-SECURITIES>                         2,710
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                           21
<TOTAL-LIABILITIES>                              2,731
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                        61,011
<SHARES-COMMON-STOCK>                            5,763
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                            4
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                         (3045)
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                        16,879
<NET-ASSETS>                                    74,849
<DIVIDEND-INCOME>                                  104
<INTEREST-INCOME>                                   94
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                     561
<NET-INVESTMENT-INCOME>                          (363)
<REALIZED-GAINS-CURRENT>                         (271)
<APPREC-INCREASE-CURRENT>                       10,212
<NET-CHANGE-FROM-OPS>                            9,578
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                            0
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                          2,779
<NUMBER-OF-SHARES-REDEEMED>                    (1,314)
<SHARES-REINVESTED>                                  0
<NET-CHANGE-IN-ASSETS>                          26,088
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                              421
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                    588
<AVERAGE-NET-ASSETS>                            56,060
<PER-SHARE-NAV-BEGIN>                            11.34
<PER-SHARE-NII>                                 (0.05)
<PER-SHARE-GAIN-APPREC>                           1.70
<PER-SHARE-DIVIDEND>                                 0
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              12.99
<EXPENSE-RATIO>                                   1.00
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

</TABLE>