Abstract: This paper examined whether and how institutional environment and media monitoring affect the auditing quality by selecting a sample listed companies in A stock market from 2008 to 2011, based on principal component analysis and Heckman sample selection model. It indicates that auditing quality can be high in better institutional environment area and media monitoring can improve it, especially negative media exposure can promote auditing quality improvement strongly. And media monitoring can make up the differences of auditing quality caused by the unbalanced development of institutional environment. That is to say the lower level of institutional environment is, the more significant effect that media monitoring improves auditing quality will be.