Farzad Karimi - Associate professor of Economics Department of Management and Economics, Islamic Azad University, Mobarakeh Branch, Isfahan, Iran
Fereshteh Nasr Esfahani - MA of Accounting, Department of Accounting Islamic Azad University, Isfahan Branch, Isfahan, Iran

Product market competition affects the corporate governance system and can increase the speed of adjustment of the capital structure. This study examined the relationship between corporate governance system, product market competition and dynamics of capital structure of listedcompanies in companies listed in Tehran Stock Exchange. Therefore, a sample of 175 firms listed in the Tehran Stock Exchange during the period of eight years (1386-1393) were selected. To test the hypothesis of multivariate regression analysis using panel data method is used. The results of the data analysis and hypothesis testing shows that competition improves the company's management is weak and then quickly adjust the capital structure of companies with increased weakness of the leadership. Also competing in companies that have strong governance structure, capital structure to reduce the speed of adjustment

capital structure, corporate governance, product market competition, speed of adjustment