本文摘要 馬英九一直都是選戰常勝軍，更是藍營的票房良藥，但是在他執政後的國民黨卻在多次立委補選敗選，是否明星光環不在？社會輿論中，更是把國民黨在近幾次立委補選的失利歸咎在中央政府的施政不佳。本研究在回溯性理論與公民複決理論的支持下，透過觀察 2009年的三場立委補選，嘗試驗證這些選民的投票行為是否會受到他們對中央政府的執政滿意度所影響。研究結果顯示，在苗栗縣第一選區的選舉中，中央施政滿意度沒有對選民的投票行為產生顯著影響。但是，在台北市第六選區與雲林縣第二選區的選舉中，選民對中央施政的滿意度對他們的投票行為產生不同的影響。之所以會出現各縣市分析結果的差異，作者相信與選舉情境差異有關。由於台北市第六選區與雲林縣第二選區的補選都涉及藍綠對決，因此泛綠在競選過程不斷以中央施政無力來攻擊泛藍候選人，讓選民會將中央施政結果列入他們的考慮中。在苗栗縣第一選區的補選中，由於是藍軍自家分裂的對決，因此這種氛圍就不再存在。

Abstract This paper analyzes the extent to which performances of the central governments could shape Legislative Yuan by-election outcomes. Based on the retrospective voting theory and referendum voting theory, this research used the survey data of Taiwan’s Elections and Democratization Studies (TEDS) to explore whether one’s assessments of the central government’s performances affect his/her choice in by-elections. There are some findings from this research: first, the result showed Miaoli’s first district voters have differing voting behavior compared to voters in Taipei City’s sixth district and Yunlin’s second district. The assessment on central government performance has no significant influence on Miaoli’s voters voting behavior; second, for the voters in Taipei City sixth district and Yunlin second district, the assessment of the central government performance have mixed effects due to the election context. As a result, we may conclude that the by-elections in Taipei City sixth district and Yunlin second district can be regarded as referenda on the central government, but the by-election in Miaoli’s first district was different from the others.