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. Second, in terms of policy questions, before the party turnover in 2000, there was no difference between the behavior of the Kuomintang legislators who were in power and the legislators of the other parties. However, after the shift in the balance of power in 2000, the legislators’ behavior in regard to the policy questions of both the Kuomintang and Democratic Progressive Party changed. That is, Democratic Progressive Party legislators became less positive toward policy questions than the legislators of the other parties when the Democratic Progressive Party became the ruling party. On the other hand, the Kuomintang legislators became more positive toward policy questions when the Kuomintang became the opposition party than when the Kuomintang was the ruling party. Third, in terms of budget and expenditure questions, before the change in the ruling party in 2000, legislators of the opposition parties were more positive toward budget and expenditure questions than legislators from the Kuomintang. However, after the election in 2000, Kuomintang legislators became more positive toward budget and expenditure questions, while legislators of the Democratic Progressive Party become more negative toward budget and expenditure questions. Finally, in terms of constituency service, after the election in 2000, Democratic Progressive Party legislators devoted more time and energy to consistency service. Regardless of the proportion of working time spent in consistency service, the size of the electorate and the number of red and white envelopes, legislators of the Democratic Progressive Party became more consistent in their service than before.