有關政府採購研究，現行大部分關注在法律層面、制度層面。本研究擬從政策變遷與宏觀角度切入，就發包中心設置過程因果關係，發現決策者信念、政策中間人、聯盟運作等對政策影響。本文擬透過Sabatier & Jenkins-Smith 所建構政策倡議聯盟架構（Policy Advocacy Coalition Framework，[PACF ]），從不同面相研究觀察，以宏觀之政策面，研究分析市府發包中心重新設置之動態過程。 本研究採文獻分析法、深入訪談及焦點團體訪談法，分析探討1995至2015年臺北市政府聯合採購發包中心設置之政策變遷過程。藉由分析架構內外在系統的影響因素，探討執政輪替與決策者的信念是否為影響政策變遷主要因素。經研究發現：第一，市府倡議聯盟間（發包中心與洽辦單位、集中採購與分散採購）透過政策導向的學習，跨越聯盟達成共識。第二，避免陳水扁時代採購案件延宕，改以折衷版集中採購。第三，柯文哲市長主張集中採購，設置發包中心政策是其競選政策白皮書。第四，市府發包中心設置政策變遷主因，決策者信念與執政輪替。 / With regard to government procurement research, most of them focus on the legal and institutional aspects. This study intends to proceed from the perspective of policy changes and macroeconomics. It will investigate the cause-and-effect relationship of the setup process of the contract issuing center, and discover the impact of decision makers' beliefs, policy middlemen, and alliance operations on the policy. Using the policy advocacy coalition framework (PACF) constructed by Sabatier & Jenkins-Smith , we observe and analyze the dynamic process of the resetting of the city's outsourcing centers. This study used document analysis, in-depth interviews, and focus group interviews to analyze and explore the process of policy changes at the Joint Purchasing and Contracting Center of the Taipei City Government from 1995 to 2015. By analyzing the influencing factors of the internal and external systems of the architecture, it is discussed whether the alternation of governance rotation and decision makers' beliefs are the main factors affecting policy changes. The study found that: First, the city’s initiative among the alliances (contracting centers and contact agencies, centralized procurement and decentralized procurement) through policy-oriented learning, reached consensus across the alliance. Second, to avoid delays in Chen Shui-bian’s era of procurement cases , it used eclectic centralized procurement. Thirdly, Mayor Ko Wen-je advocated centralized procurement and set up a contract center policy as a white paper on his election policy. Fourth, the main reasons for the policy changes in the city's outsourcing centers are decision makers' beliefs and governance rotation.