This paper selects China's A-share listed companies from 2013 to 2018 as research samples to empirically test the relationship between institutional environment, government subsidies and enterprise R&D investment, and further analyzes the impact of enterprise ownership on the above relationship. The empirical results are as follows: institutional environment and government subsidies are conducive to increasing enterprise R&D investment; the institutional environment strengthens the incentive effect of government subsidy on enterprise R&D investment; compared with state-owned enterprises, institutional environment and government subsidies have a stronger promoting effect on R&D input of non-state-owned enterprises.