本研究主要目的在探討2000年政黨輪替對立委立法問政與選區服務行爲的影響。本研究發現：一、在法律提案方面，國民黨和民進黨立委在政黨輪替前後出現明顯改變。不論是國民黨或民進黨立委，在野時的法律提案次數皆高於執政時。顯示兩黨立委的法律提案行爲會因爲其執政或在野的差異而有不同的行爲模式；二、在施政質詢方面，在政黨輪替前，執政的國民黨和其他在野黨立委之間並無明顯差異，不過在政黨輪替之後，則可以發現兩黨立委開始有了明顯的改變，亦即成爲執政黨的民進黨立委在質詢上不如其他在野黨立委積極，而成爲在野黨的國民黨立委則是在施政質詢上變得比其在野時積極；三、在預決算質詢方面，在野黨立委在政黨輪替前較執政的國民黨立委踴躍，然而在政黨輪替之後，成爲在野黨的國民黨立委在預決算質詢上則變得較過去在野時積極，而成爲執政黨的民進黨立委則是轉爲消極；四、在選區服務方面，民進黨立委在政黨輪替後，投入較多的時間和精力在選區上。不論是在選區服務工作時間比例、選民服務個案數以及紅白帖數目上，處於執政地位的民進黨立委皆比處於在野地位的民進黨立委在選區服務上來得多。

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.