在基础设施领域中利用政府和社会资本合作（Public-Private Partnership，简称PPP）模式可以有效发挥政府和社会资本的优势，提高供给效率，然而契约的不完备性及项目内外部条件的不断变化导致了实践中PPP项目再谈判多发和低效的问题愈发凸显。正确认识并运用再谈判能够提升项目对风险的适应能力，保持项目的长期稳定性，因此有必要对再谈判的影响因素和触发机理进行研究，提高再谈判的治理效率。首先，本文在梳理总结再谈判的理论基础，明确再谈判的原则、流程与结果的前提下，通过文献和案例分析，对触发再谈判的影响因素进行了识别与筛选，并结合专家访谈，修正和确定了囊括PPP项目全生命周期的24项影响因素。接着利用问卷调研，分析了影响因素的权重，除了确定各因素的重要性排序之外，通过方差分析发现不同参与者视角下因素的重要性存在差异，如社会资本方和第三方机构对于市场风险的重要性评分均显著高于政府方。而后采用因子分析法将影响因素提炼为更具有代表性的6个公因子：前期工作、项目过程管理、合同设计、政府行为、社会资本方行为和环境因素，并分析了各公因子的重要性。其次，本文筛选了28个典型的PPP再谈判案例，利用定性比较分析的方法求解出触发再谈判的五种典型原因组态，包括政府行为不当主导的组态、环境变异与社会资本行为不当的终止合作组态、前期工作欠缺与社会资本行为不当的组态等，其中44%的案例能被政府行为不当这一核心条件与环境因素变异这一边缘条件结合的组态解释。结合具体案例和相关理论对每种组态内部相互作用机制和再谈判的触发机制进行阐述，揭示了PPP再谈判事件的多重并发因果关系。最后，针对再谈判实践中的要点，本文构建了经过验证的包含再谈判识别、执行与支撑机制的管理流程框架，提出了政府、社会资本和治理机制三个角度的再谈判管理建议，如政府应注重前期工作、完善制度基础，社会资本方应正确认识并应对风险、建立良好合作心态，重视合同治理与关系治理的结合作用等。本文结论能为完善再谈判相关制度建设，提高PPP再谈判乃至全过程的治理效率提供参考。

In the field of infrastructure development, using Public-Private Partnership (PPP) model can effectively take advantage of government and social capital, improving the supply efficiency of projects. However, the incompleteness of the contract and the changing internal and external conditions of the project have led to the frequent and inefficient renegotiation of PPP projects in practice. Proper understanding and application of renegotiation can improve the adaptability to risks and maintain the long-term stability of the project. Therefore, it is necessary to study the influencing factors and triggering mechanisms of renegotiation to improve the governance efficiency.Firstly, on the premise of summarizing the theoretical basis and clarifying the principles, processes and results of renegotiation, this thesis identifies and selects the influencing factors of renegotiation through literature research and case summary and distinguishes and further improves 24 influencing factors covering the whole life cycle of PPP projects combined with expert interviews. Then this thesis uses the data of questionnaire survey to analyze the weight of each influencing factor. Variance analysis shows that the importance of factors from different participants' perspectives is different. For example, the importance scores of social capital and third-party institutions for market risk are significantly higher than those of government. Next，the influencing factors are refined into six indexes by factor analysis, which are preliminary work, process management, contract design, government behavior, private behavior and environmental factor, and the importance of each index is analyzed.Secondly, this thesis selects and summarizes 28 typical cases of PPP renegotiation, and uses the method of clear set qualitative comparative analysis to find out five typical triggering configurations of renegotiation, including improper government behavior, termination of cooperation due to environmental variation and improper private behavior, lack of preliminary work and improper private behavior, etc.Among them, 44% of the cases can be explained by the configuration of the core condition of improper government behavior and the auxiliary condition of environmental variation. Combined with specific cases information and theories, the internal interaction mechanism of each configuration and the triggering mechanism of renegotiation are elaborated, revealing the characteristic of PPP renegotiation is multiple concurrent causality.Finally, aiming at those key points in the practice of renegotiation, this thesis constructs a validated management process framework including the recognition, implementation and support mechanism of renegotiation, and puts forward renegotiation management suggestions from perspectives of government, social capital and governance mechanism，such as government should pay more attention to the preliminary work, improve legal system of renegotiation, social capital should correctly recognize and deal with project risks and actively establish a sound cooperation relationship, and for project management should emphasis on the combination of contract governance and relationship governance. These conclusions can provide reference for improving the governance efficiency of PPP renegotiation and even the whole project management.