德國從十九世紀以來的憲政發展，整體而言是持續朝議會民主的目標逐步前進。雖然在十九世紀就出現了議會民主的思潮，但就行政與立法的關係來看，墊個十九世紀的憲政發展都呈現一種緊張的雙元關係，而且行政權始終保持著一定程度的獨立性與優越。直到二十世紀初，一次世界大戰摧毀了君權，威瑪憲法被視為德國第一部議會民主的憲法。受到成瑪共和建立時的妥協性格，以及十九世紀行政立法二元緊張關係的影響，成瑪憲法在議會民主的外衣下，仍潛藏著行政的獨立與優越性格，行政權潛在的優越性甚至在制度上成為一九三三年希特勒執政的因素之一。戰後的聯邦基本法，持續以建立一個完善的議會民主為目標，而成瑪憲法的實踐經驗成為基本法最重要的參考依據。本文認為，基本法欲建立以議會為核心的憲政秩序，在制度上有很多可欲的改變。包括建設性不信投票、信任投票、總統產生方式、解散國會等等、透過這些設計比較成瑪憲法與基本法的差異可以發現，基本法希望透過建立正常的政黨國家，來達成議會民主的目的。

The goal of Germany's constitutional development from 19 century is to establish a parliamentary democracy. The relationship between the executive and legislature was asymmetric and the executive power was even stronger although the parliamentary thought emerged from 19 century. Until the beginning in 20 century, the monarchy was breakdown because the failure of the First World War. And the Weimar Constitution was deemed as the first parliamentary constitution of Germany. However, the Weimar Constitution was a product with the compromise. The potential superiority of the executive was still within the constitution. It was even the institutional factor which caused Adolf Hitler to obtain the regime. The Basic Law after the Second World War was still adopted with a goal to reach a parliamentary democracy. And the Weimar Constitution was the most important experience. This paper tries to discuss the evolutional parliamentary democracy from the Weimar Constitution to the Basic Law within the designs such as the constructive non-confidence vote, confidence vote, election of the president, and the dissolution of parliament etc. We believe that the Basic Law wishes to establish a parliamentary democracy on the basic of a party-state.