基于双重差分模型考察我国上市企业纳入MSCI指数与其投资决策的关系，研究发现纳入该指数会影响企业的投资水平和投资效率。具体而言，纳入指数主要影响拥有境外业务、管理层持股类企业的投资决策，在这些企业中，投资不足的企业投资水平显著提升，但投资效率有不显著的下降；投资过度的企业投资水平有不显著的提升，但投资效率显著下降。总体而言，纳入MSCI指数整体上提升了拥有境外业务、管理层持股类企业的投资水平，但是其投资效率则呈现下降趋势。纳入MSCI指数对我国资本市场发展的积极作用有待进一步观察。

This paper studies the influence of being members of MSCI Emerging Market Index on investment decision of Chinese listed enterprises based on the difference-in-difference model. We find that being members of MSCI Index affects both level and efficiency of the investment. Specifically, being members of MSCI Index mainly affects the investment decision of enterprises with overseas business and management shareholding. In these enterprises, the investment level of enterprises with insufficient investment increases significantly, while the investment efficiency decreases with no significance; The investment level of enterprises with excessive investment increases with no significance, while the investment efficiency decreases significantly. In general, being members of the MSCI Index increases the investment level of enterprises with overseas business and management shareholding, while the investment efficiency shows a downward trend. Thus a further observation is necessary to examine the positive effect of this inclusion index on the development of Chinese capital market in the future.