The purpose of this study is to examine the relationship between earnings management and firms’ credit ratings. Furthermore, this study explores association between earnings management and credit ratings under existence information asymmetry. Based on previous studies, this study proposes that firms engaged in earnings management would influence firms’ credit ratings. Therefore, the behavior of firms manipulated their earnings will increase the profitability of firms’ default as well as will influence the credit ratings of the firms. Also, this study suggests that earnings management and credit ratings are positive relationship under existence of information asymmetry and undetected earnings management. Empirical results show that, information asymmetry is significantly positive related to earnings management.earnings management is significantly negative related to credit ratings, under existence of information asymmetry. It represents that higher information asymmetry is more likely to implement earnings management, and have more opportunity to improve in their credit ratings.