Objective: Earnings quality is one of the most substantial features of financial reporting, influencing the optimal capital structure. This substantiality probably results from the fact that earning is generally considered as one of the main inputs of valuation models for both financial investors and analysts. This research aims to investigate the simultaneous effect of corporate governance and audit quality on accounting earnings quality, using structural modeling. Method: With a sample of 2006 to 2015 and 700 firm-years, to analyze the data of the research period, structural equation modeling with partial least squares (PLS) approach and Smart-PLS software have been applied. Results: The results of this research indicate that corporate governance and audit quality, directly and indirectly, through the mediating variable of financial performance, have a significant positive effect on the earnings quality ؛ while, through the mediating variable of capital structure, the effect is significantly negative. Furthermore, our findings reveal that the direct impact of corporate governance and audit quality on earnings quality is stronger than their indirect effect.