文章基于文献研究和对科技智库影响力的本质判断，借鉴传播学、创新扩散理论和政治分析理论思想，从“主体-对象-环境”体系角度，构建了科技智库影响力的基本要素模型，提出了社会资本、思想产品、受众对象、影响渠道、介入时机和产品市场六大基本要素，以美国科学院、英国皇家学会和印度科学院为例进行了案例分析。总之，科技智库影响力是资源要素、终端要素、对象要素、路径要素、时间要素、空间要素综合发挥作用的结果。

By the literature study and essential judgment of think tanks’ influence, and applying the ideas from mass communication, innovation diffusion, and political analysis, from the triality of “subject-target-environment”, this paper proposes six fundamental factors of think tanks’ influence, i.e. social capital, thought product, audient target, influence channel, intervention opportunity and product market. It constructs a model for these factors, and studies the cases of the Academy of Sciences - U.S.A., the Royal Society - G. B., and Academy of Sciences - India. Finally, it concludes that think tanks’ influence is the result of synthetical operations of resource factor, terminal factor, target factor, path factor, time factor and space factor.