Selecting the annual data of 8972 A-share listed companies in Shanghai and Shenzhen Stock Exchange from 2006 to 2014 as research sample, this paper makes an exploration on the relationship among institutional investor, accounting conservatism and enterprise investment efficiency.The results show that accounting conservatism significantly improves enterprise investment efficiency. Compared to the transactional institutional investors, stable institutional investors can strongly promote accounting conservatism and improve enterprise investment efficiency.The results of the study prove the symmetry between the function of pricing and governance about accounting conservatism improving enterprise investment efficiency.The paper also examines the view of institutional investors to promote accounting conservatism and improve the pricing and governance about enterprise investment efficiency.