<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> 01
   <NAME> LARGE 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>                          771,576
<INVESTMENTS-AT-VALUE>                       1,130,641
<RECEIVABLES>                                    4,809
<ASSETS-OTHER>                                       0
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                               1,135,450
<PAYABLE-FOR-SECURITIES>                         8,539
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                          147
<TOTAL-LIABILITIES>                              8,686
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                       777,691
<SHARES-COMMON-STOCK>                           43,016
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                         (38)
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                        (1,050)
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                       350,085
<NET-ASSETS>                                 1,126,764
<DIVIDEND-INCOME>                                8,574
<INTEREST-INCOME>                                  547
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                   3,765
<NET-INVESTMENT-INCOME>                          5,356
<REALIZED-GAINS-CURRENT>                       104,660
<APPREC-INCREASE-CURRENT>                      198,191
<NET-CHANGE-FROM-OPS>                          308,207
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                      (5,356)
<DISTRIBUTIONS-OF-GAINS>                     (104,621)
<DISTRIBUTIONS-OTHER>                             (39)
<NUMBER-OF-SHARES-SOLD>                          5,424
<NUMBER-OF-SHARES-REDEEMED>                    (2,861)
<SHARES-REINVESTED>                              4,217
<NET-CHANGE-IN-ASSETS>                         372,366
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                            3,446
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                  3,765
<AVERAGE-NET-ASSETS>                           914,150
<PER-SHARE-NAV-BEGIN>                            20.82
<PER-SHARE-NII>                                   0.14
<PER-SHARE-GAIN-APPREC>                           8.05
<PER-SHARE-DIVIDEND>                            (0.14)
<PER-SHARE-DISTRIBUTIONS>                       (2.68)
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              26.19
<EXPENSE-RATIO>                                   0.41
<AVG-DEBT-OUTSTANDING>                               0
<AVG-DEBT-PER-SHARE>                                 0
        

</TABLE>