政治信任是民眾對政府施政結果與民眾期望之間一致性程度的認知。民眾的政治信任有其理性思考的基礎，也有其政治後果。本研究主要運用2004 年「臺灣選舉與民主化調查」（Taiwan’s Election and Democratization Study, TEDS ）在2004 年立法委員選舉之後所進行的訪問資料，結合過去自1992 年以來歷次立委選舉之後進行的共五次調查資料，分析民眾政治信任的趨勢以及影響民眾政治信任的因素與民眾政治信任對其投票行為的影響。本研究發現自1992 年到1998 年之間，民眾政治信任逐年下滑。雖然在2001 年中央政權政黨輪替之後，出現短暫的止跌，不過，卻在2004 年跌到十幾年來的最低點。就影響民眾政治信任的因素而言，除了民眾所屬的政治世代與省籍之外，民眾對於執政黨的好惡程度以及對於過去一年來經濟情況的回溯性評估，都有顯著影響。而2004 年立委選舉中，影響民眾投票支持泛綠陣營或是泛藍陣營候選人的因素中，除了民眾的政黨認同與臺灣人認同之外，民眾對於陳水扁總統過去四年的施政表現評分以及政治信任的高低，都有顯著的影響。

Political trust is the degree to which citizens perceive that government performance is consistent with their expectations. The citizens’trust in the government has rational causes and political consequences. In this study, we employ the data set from the Taiwan’s Election and Democratization Study (TEDS 2004L B) and four other previous surveys on legislative elections to explore the trends in political trust, the factors affecting political trust, and the political consequences of political trust. We demonstrate that, between 1992 and 1998, the level of political trust declined monotonically. Though the decline froze in 2001 after the Democratic Progressive Party (DPP) took power in 2000, it dropped to its lowest level in 2004. As for factors affecting levels of political trust, aside from ethnic backgrounds and the political generations to which people belong, both people’s feelings towards the ruling party and retrospective evaluations of the economy affected their level of political trust significantly. As for major variables determining voters’choices in the 2004 legislative elections, political trust, partisan preference, Taiwanese identity, and the approval rate of President Chen’s performance over the past four years played major roles in influencing voter choices.