1990年統一前，東德由德國社會主義統一黨進行威權統治，西德則為一個自由民主國家，政黨在公平的競爭制度中運作。兩德統一後，政治制度迥異的兩個體系在重整過程中，必然會出現嚴重的磨合現象。不同於以往探究政黨體系僅重視體系內單純的「相關性政黨數字」的變化，與政黨「意識形態」距離與強度的差異，本論文試著從「社會分歧」(social cleavage)出發，觀察德國統一以來，社會結構分歧程度與政黨反應此基礎所呈現的互動關係，並說明政黨勢力的興衰，如何合作結盟或是分裂結構，已呈現德國政黨體系的內涵特色。另外，也結合「政黨體系變遷」與「政黨體系分類」理論，試圖針對政黨體系的內涵，包括政黨體系變遷的成因與內容，以及對政治體系的影響做探討，來探究德國政黨體系的動態內涵。最後，也從德國政黨體系的研究歷程中，提出德國因統一而起的「整合價值」分歧，可能正在形成，進而印證分歧理論在德國政黨體系的適用性。

Before German unification in 1990, East Germany/GDR was authoritarian-governed by the Socialist Unity Party of Germany and West Germany/FRG was a democratic state with a relatively fair competitive party system. Serious conflicts between totally different political systems must have emerged when they started to become a unified state. Differing from the traditional approach to studying party systems through party numbers and ideologies, the author will, through “social cleavage,” examine how German parties reflect the change of the social structure after German unification. In other words, cooperation, alignment and even dealignment among German parties and the characters of the German party system after unification will be emphasized in this research. To combine the changes of party system and classification of party system, readers will realize the reasons, contents and influences of the German party system after 1990.Finally a conclusion is summarized: the integration probably have formed a specific German social cleavage after unification.