本文总结了凯恩斯储蓄———投资模型的贡献和不足及其后继者所做的修补 ,考察了该模型理论在美国和中国不同时期的需求管理政策效应 ,并得出了两个有益的启示 :第一 ,凯恩斯药方不能无条件地滥用 ,因为其本身存在长期负效应 ;第二 ,要转变投资观念 ,应重点对准基础设施和教育 ,这才是有利于长期发展的关键。 This paper summarizes the contributions and deficiencies of Keynesian savings --- investment model and the repairs done by its successors. It examines the demand management policy effects of the model theory in different periods in the United States and China and draws two beneficial enlightenments: First, Keynes’s prescription can not be abused unconditionally because of its long-term negative effect. Second, to change its investment philosophy, it should focus on infrastructure and education, which is the key to long-term development.