Information transparency disclosed are more and more paid attention by market participants. In order to reduce the negative impacts of information asymmetry, Taiwan authority built the evaluation system of information disclosure for the firms listed in TWSE and OTC since 2003. By employing the firms listed in the TWSE and OTC as our samples, we explore whether information asymmetry and voluntary information disclosure would affect firm value after controlling corporate governance and financial statements variables. The results reveal that the firms with high degree of information transparency and voluntary information disclosure would have higher firm value; on the contrary, the firms with lower degree of information transparency might not weaken firm value.