Abstract:Research and development is a key resource of scientific and technological advances for a country. This study chooses the listed firm data in mainland China from 2003 to 2014 and empirically tests the effect of independent directors on R&D based on principal-agent theory. The results show that the ratio of the number of independent directors in board can significantly enhance R&D investment, even considering high-technology industry which has higher R&D investment ratio and controlling endogenously. Furthermore, This study investigates the influence of institution environments and the results show that the property right and the level of legal protection have significant effect on the relationship between independent directors and R&D. The conclusions of this study provide macro and micro views on current innovation society.