The aim of the research is to study impact of corporate governance and information of investor confidence on earning management of firms listed on the Stock Exchange of Thailand. Stratified random sampling technique was employed in order to obtain the required sample of 408 Thai-listed companies. The study have excluded financial companies because their capital structure and profit are different. The study uses annual data of companies in 2015. The results showed that the highest shareholders impact on earning management, the proportion of institutional investors influencing both the earning management and investor confidence, and companies with BIG4 have an influence on investors' confidence. However, board size and CEOs Duality did not find any influence on earning management and investor confidence.