Information transparency enhances corporate governance. In an attempt to reduce the information asymmetry between business insiders and outsiders and to allow outsiders to have more information for decision making by disclosing more corporate information voluntarily, the Taiwan Stock Exchange Corporation (TSEC) and Over-The-Counter Securities Exchange (OTCE) requested the Securities & Futures Institute (SFI) to implement an information disclosure and evaluation system for all publicly traded and OTC companies listed in TSEC. This study investigates the effects of the system on decision behavior of the investors, analysts, and auditors. Empirical results indicate that investors¡¦ ability of future earnings evaluation increases, analysts¡¦ earnings forecasts are more accurate, and the earnings forecasts dispersion among the analysts decreases after the system has been implemented. However, the implementation of the system has no effects on the types of audit opinion issued by auditors. Besides, the analysts¡¦ earnings forecasts are more accurate for the ¡§more transparent¡¨ companies. However, the differences of future earnings evaluation, earnings forecasts dispersion among the analysts and types of audit opinion between ¡§more transparent¡¨ and ¡§less transparent¡¨ companies are not significant. These results may provide implication to authorities for making related policies.