Abstract: Few studies focus on the relationship between state ownership and long-run IPO performance, and government regulations haven’t been taken into account. This paper selected the data of A-share IPO companies from 1990 to 30 June 2011 as sample, examined the effects of state ownership on long-run IPO performance and government pricing regulations on the relationship between state ownership and long-run IPO performance. Cluster regression results show that long-run IPO performance decreased with state ownership, and long-run IPO performance decreased with state ownership in the government pricing regulations firms. This paper deepens the research about the effects of state ownership on long-run IPO performance, helps to know more about government behavior and its influence in process of the privatization of state-owned enterprises, and helps to understand the relationship between government, enterprise and market in process of the development of the Chinese securities market.