The purpose of this study is to probe into the effects of party turnover in 2000 on the behavior of legislators in terms of law-making and constituency service. The findings of this study are as follows. First of all, in terms of law-making, the evidence clearly shows that legislators of both the Kuomintang and Democratic Progressive Party change their mode of behavior regarding legal proposals. That is, both sets of legislators make more legal proposals when their party is out of office than when their party is in office.