This Study investigates the Relationship between corporate governance and earning quality the listed companies in Tehran stock exchange, over the period of 2002 through 2008. In this study following Gov-Score developed by Brown and Caylor (2006), the corporate governance has investigated by using features of dual responsibility of CEO, board of directors independent, board of directors size, board of directors ownership, institutional investors ownership, auditor size, auditor tenure, CEO tenure and law merchant compliance. To determinate of earning quality based on modified Jones (1991) model, used from absolute value of discretionary accruals. For test of hypothesis are used the variance analyse (ANOVA) and multiple linear regression and measurement method of Cross-sectional. We find evidence that there is no significant relationship between all of the features of corporate governance used in this study and earning quality. Also, there is no significant Difference between earning quality of companies with strong, medium and weak corporate governance.