自西元前二二一年秦始皇統一全國以來，中國便逐步邁向以中央集權為特色的帝國制度時代。儘管所謂「皇帝」在其後的二千一百三十二年間始終被放在整個政治體系的最中心位置，且被賦予無可抗衡的絕對權力，但由於君主本身素質的不穩定，再加上政事之複雜必有賴其他官僚的輔佐，因此俗稱為「宰相」的行政體系領導者之角色也自然突顯出來。進一步析之，實際上運作政權的宰相經常由於可能挑戰僅具名義上統治地位之皇帝的權威，而引發後者之不安全感與自我保護感，於是也導致後者透過制度設計企圖削弱前者的能力。本文即嘗試透過此等權力自然互動脈絡的長期發展，來觀察中國上層政治制度的變化。

　　　　　Since B.C. 221, when the First Emperor of the Ch’in Dynasty unified China, it entered a centralized Imperial Period. Although all the emperors since then were put in the central position of the whole political system and owned peerless, absolute power, the instable quality of the ‘Emperor’ and complications of political affairs still made the ‘Premier’ more active and powerful. Owing to the emperors’ sense of a lack of security and need for self-protection, the former usually tried to limit the premiers’ power through restructuring the political institutions. In this paper, I want to explore further the interaction of the Chinese emperors and their premiers by observing the transitions in the upper tiers of the political system.