我國立法委員選舉自1992年全面定期改選以來，一直是採用以「複數選區單記非讓渡投票制」為主的特殊選舉制度，直到2005年第七次修憲始變革為「並立式混合制」，並已於2008年1月12日第七屆立委選舉中首度實施。 由於台灣與日本均位居東亞關鍵位置，並同為該區民主發展之典範，類似的政經發展脈絡，於是經常成為學界探討比較的對象。除了近似的經濟發展模式外，於政治層面上，兩國亦皆由「一黨獨大」的政體開始演變。尤其，兩國更先後於1994年及2005年修改國會選舉制度，且不約而同從「複數選區單記非讓渡投票制」改採「並立式混合制」。 任一國家選舉制度之變革，往往都會對其政黨體系、甚至政治運作造成相當程度之影響。因此本研究將針對此次選舉所採取的新選制，從理論、制度及實際各層面，參照日本選制改革與施行之經驗，進行新選制對我國政黨體系影響之初探。 / The overall election of legislator in our country has been reelected regularly since 1992, and it has been adopting primarily the “Single Non-Transferable Vote with Multimember-District system” (SNTV-MMD), a special electoral system. Until the seventh amending of the Constitution transformed into the “Mixed-Member Majoritarian” (MMM) in 2005, which has implemented in the seventh session of legislators’ election for the first time in January 12, 2008. Owing to both of the positions of Taiwan and Japan are very important in the East Asia, and also are the models of the development of democracy in the area. They have similar political and economic developing situation, so they are usually compared to each other by the academic community. Besides the similar economic development pattern, in the political side, both of the two countries began to evoluting from “predominant-party system”. Above all, the two countries reformed the electoral system of congress in 1994 and in 2005. They also adopted the “MMM” instead of the “SNTV-MMD” coincidentally. Changes of the electoral system in any country will impact on party system even political arrangement in a considerable degree. Therefore, I’ll focus on the new system of this election from the different sides of theory, institution, and reality in this research. According to the reformation of the electoral system of Japan and the practical experiences, doing a preliminary study of how the impact of the new electoral system on Taiwan’s party system.