中文摘要：

论文以中国A股上市公司2005～2006年的横截面数据为基础，分析了大股东持股及其相关的股权结构特征对管理者过度投资行为的治理效应。结果表明：（1）大股东持股比例与企业的过度投资水平呈一种倒“N”型的曲线关系，即大股东对管理者过度投资行为的监督作用同时存在激励效应和防御效应；（2）非国有大股东对管理者过度投资行为的监督更有力；（3）次大股东的存在有利于发挥大股东的激励效应，抑制大股东的防御效应，特别是当大股东不处于控股地位时。

英文摘要：

Using cross-sectional data of A-share listed companies in China from 2005 to 2006, this paper analyzes the governance effect of large shareholders and ownership structure＇ s characteristics on managerial over-investment behaviors. The results show that： firstly, there is a nonlinear inverse-N shape relationship between large shareholders＇ share and firms＇ over-investment level. That is, large shareholders have the incentive effect and entrenchment effect on managerial over-investment behaviors. Secondly, state large shareholders have less incentive to monitor managerial over-investment behaviors. Thirdly, second largest shareholders will induce large shareholders＇ incentive effect and control their entrenchment effect, especially when large shareholders＇ share is relatively small.