中文摘要：

社会资本作为公共项目的客观情景因素，能够弥补公共项目中正式制度的不足并改善项目管理绩效。文章分析了社会资本三个维度对管理绩效的影响，围绕着公共项目管理绩效的可控影响因素，引入知识共享作为中介变量，在公共项目中构建出“社会资本→中介变量→公共项目管理绩效”的假设模型，并依此完成实证研究。结构方程模型（SEM）的验证结果表明，在社会资本与公共项目管理绩效之间的作用关系中，知识共享充当了中介变量的角色，社会资本各构面在不同程度上对公共项目管理绩效产生间接的正效应。

英文摘要：

Social capital, as an objective situational factor of public project, could compensate for the drawbacks of the for- mal system and improve management performance for public projects. This paper studies the effect of the three dimensions of social capital on management performance, introduces knowledge sharing as mediating role based on controllable factors of public project management performance, and constructs the hypothesized model of ＇social capital→the mediating vari- ables→public project management performance＇ in public project, and then carries out an empirical study. The resuhs of structure equation modeling （SEM） show that knowledge sharing plays a role of intermediary function in the influence rela- tion between social capital and public project management performance, Each component of social capital has an indirect positive effect on pt, blic project management performance at different degrees.