With the data of China’s listed companies during the period of 2007-2012 as a sample, this paper makes an analysis on the relationship between accounting conservatism, product market competition and firm’s future stock price crash risk. The results indicate that the accounting conservatism is significantly positive correlation with stock price crash risks, more competition in product market is associated with less stock price crash risks in the future. We also confirm that product market competition reinforces the relationship between accounting conservatism and stock price crash risk. It suggests that both accounting conservatism and product market competition play a significant role in corporate governance, and there exists a complementary relationship between product market competition and accounting conservatism in terms of reducing crash risk.