中文摘要：

针对我国上市公司股权集中对研发投资的影响在现实和理论中均存在不同表现的现状,基于双重委托代理理论,收集2009-2012年上市公司动态面板数据进行分析。研究结果表明：（1）中国上市公司中股东和经理人之间的委托代理矛盾与大股东和中小股东之间的委托委托矛盾相比较而言,后者比前者更为严重。因此,提高当年的股权集中度不仅会降低当年的研发投资,而且随着股权集中度的增加,当年研发投资降低的速度越来越快,这种影响会持续到第二年,但是影响程度会低于第一年。（2）随着公司市场价值的增加（即托宾Q越大）,股权集中度对研发投资的负向影响程度会降低;随着公司现金流的增加,股权集中度对研发投资的负向影响程度会增加;不同行业中股权集中度对研发投资的影响并没有显著的差异性。

英文摘要：

In view of the fact that the ownership concentration of Chinese listed companies has different effects on the RD both in practice and in theory,this paper collects 2009- 2011 dynamic panel data of the listed companies to make an analysis based on the dual agency theory. The results are as follows：（ 1） Compared with the principal-agent contraditctions,the principal-principal contraditctions are more serious in Chinese listed companies. Therefore,current year＇s RD investment will not only decrease,but decrease faster and faster with the incerase of the ownership concentration. This effect will continue into the next year,but to a lesser extent.（ 2） The negative impact of ownership concentration on RD investment will decrease with the increase of the market value of the company（ i. e. the greater Tobin＇s Q）,wheras the negative impact of ownership concentration on RD will increase with the increase of the company＇s cash flow. However,there is no significant difference in the impacts of townership concentration on RD in different types of industry.