Abstract: Using the data of Shanghai and Shenzhen A-share listed companies from 2007 to 2017，this paper investigates the impact of accounting conservatism on Ｒ＆D investment，and further tests the role played by ownership，heterogeneous institutional investors and information transparencyThe results show that the higher the accounting conservatism is，the less the Ｒ＆D investment of enterprises is，indicating that accounting conservatism will restrain the Ｒ＆D investment of enterprises． It is found through further tests based on the nature of ownership that accounting conservatism has a stronger inhibitory effect on Ｒ＆D investment in non-state-owned enterprises than that in state-owned enterprises; while stable institutional investors and the improvement of enterprise information transparency can alleviate the negative impact of accounting conservatism on Ｒ＆D investment．This study is of theoretically and practically significance for comprehensive under-standing of the impact of accounting conservatism on enterprise investment activities and how to reduce the negative effect of accounting conservatism on Ｒ＆D investment．