中文摘要：

从机构投资者自我保护的视角出发，通过构建公司内部人和机构投资者的博弈模型，揭示了机构投资者对其持股公司绩效影响的微观机制．在此基础上，实证研究我国沪深A股市场2004年-2012年公司样本．结果表明：机构对其持股公司绩效的改善作用在2004年-2007年和2008年-2012年两个阶段存在结构性变动；从整体来看，在上述两个阶段，机构投资者对其持股公司绩效有显著改善作用，但第二阶段的改善作用明显减弱；基金有助于改善其持股公司绩效，而其它机构投资者缺乏这种改善作用。机构在第二阶段改善作用减弱的主要原因是，在样本期间，基金持股规模占比迅速衰减，其它机构投资者持股规模占比大幅提高抑制了整个机构对其持股公司绩效的改善作用．

英文摘要：

Considering institutional investors＇ self-protection, a game model between insiders and institutional investors is built to reveal the micro mechanism how institutional holdings influence corporate performance. An empirical test is performed on the listed firm samples in Shanghai and Shenzhen A Stock Market between 2004 -2012. The results show the structural change of the effects of institutional investors on corporate per- formance during the first period （2004 -2007） and the second one （2008 -2012）. The results also show that although during these two periods the institutional investors as a whole had positive effects on corporate per- formance, the effect in the second period was obviously weaker than in the first period. The mutual fund hold- ings rather than the other institutional holdings could improve corporate performance. The main reason is that during the sample period, the holding ratio of the mutual fund decreased and the ratio of other institutional in- vestors increased rapidly, which resulted in the overall weakening of the positive effect of the institutional in- vestors on corporate performance.