Taiwan experienced rapid economic development and social family structure transition, the ratio of parent living with children gradually increased. Our research analysis reason which affect married women labor force participation and analysis the possible factors behind the phenomenon. The research adopted “Manpower Utilization Survey, MUS”, “Survey of Family Income and Expenditure, SFIE” databases. It is expected to enforced the consistency of result through the two different databases. Our results shows that even if Taiwan experienced rapid economic change, transition of social family, the Western influences and so on, the tradition that parents take care of their grandchildren has been passed down, so that lightening the household chores of the married women and increasing their employment rate.