Taking Chinese A-share listed companies from 2007 to 2012 as samples, this paper makes an empirical research on the influence of inspect investment opportunity set, internal control and their interaction on real earnings management. The results show that the motivation of real earnings management will significantly diminish with the increase of investment opportunity set. Taking the effect of internal control mechanism into account, the inhibitory effect is more obviously. After the process of marketization and property rights, the influence of the interaction between the investment opportunity set and the internal control on real earnings management is significant, especially in the areas with high process of marketization and the state owned companies.