Corporate aggressive tax activities is a kind of agency problem, agent characteristics undoubtedly influences corporate tax behavior. Based on the data of Chinas A share listed companies from 2007 to 2011 as a research sample, this paper explores CEO power influence to corporate tax aggressiveness by viewing CEO power as an agent characteristics entry point, as well as a restraint function of certified public accountant audit as the external supervision mechanism. Our empirical research suggests that the corporate with stronger CEO power has higher corporate tax aggressiveness, and further, after the audit supervision mechanism, audit industry expertise of appointed accounting firm has a significant inhibitory effect on this relationship. The research conclusion of this paper may provide a useful reference and experience support for tax policy formulation and supervision mechanism perfection.