This paper focuses on the legal case of Shanghai social security fund. Firstly, based on the annual reports and temporary announcements of public listed companies registered in Shanghai from 2004 to 2008, as well as some reports from news media, this paper manually collects political connections data of key top managers of sample companies and the involved data .Secondly, it empirically studies the relation between political connections and involved behaviors, and the impact of involved behaviors on audit opinions before, during and after the case. The results show that among sample companies registered in Shanghai, the ones with political connections have a significantly higher possibility to be involved in the case than others. In 2006 when the legal case was exposed, involved companies have a higher possibility of receiving unqualified audit opinions; however, from the year 2004 through 2005 and from the year 2007 through 2008, the possibility of involved companies to receive unqualified auditor opinions from auditors was lower.