After the enactment of Securities Exchange Act of 2006, the publicly listed companies could establish an audit committee to replace their supervisors. By selecting samples from publicly listed firms from 2007 to 2010, this study aimed to explore the impact of the establishment and characteristics of an audit committee on firm performance and information disclosure quality. The empirical results show that firms with audit committee have better market performance and information disclosure quality than firms without audit committee. In addition, firms with more audit committee members have better market performance and higher level of information transparency. The more audit committee members holding several directorships concurrently, the better expertise they can offer to enhance information disclosure quality. However, it is not significantly related to market performance.