The relationship among ownership structure and risk of banks is one of the main issues in the money and banking literature and has been considered empirically in recent years. Hence, the aim of this paper is to investigate the impact of ownership structure on the behavior risk of private and public banks with a sample of 15 banks during the 2005-2014. For achieving this objective,  two models have been estimated by applying dynamic panel data approach for these groups of banks. The main findings of this study indicate that the ownership structure has a positive effect on the return of banks and the risk of private banks is less than of other public banks after the implementation of privatization rule. Moreover, the leverage effect and growth of GDP has positive effects on the return of banks over the period of study.