Environmental performance evaluation is an important research issue in the related fields of enterprise environmental management behavior.Based on the sample of A-share listed companies in China from2008 to 2013,this paper examines the impact of media coverage on corporate environmental performance by using the"PM2.5 beyond index"event as an exogenous shock.The results show that media coverage can significantly improve corporate environmental performance,but has weakened after the"PM2.5 beyond index"event.Further research shows that the increase of public pressure which"PM2.5 beyond index"event brought weakens the media attention to the enterprise environmental performance improvement effect,and in the companies with low quality of internal control and the industry with strong competition,this phenomenon is more obvious.The research results of this paper have certain enlightenments on how to motivate enterprises to undertake environmental governance responsibilities,and also expand the existing academic researches.