The purpose of this study is the comparative investigation of difference between ownership structure and cost of capital in capitalized and levered companies of TSE. The population of this study is 81 listed companies in the TSE during the period of 2003 to 2009. Studied variables in this study include ownership structure as independent variable that it is divided into two variables, type of ownership and the degree of ownership concentration. Ownership type in this study is divided into four classes including governmental, institutional, individual and private ownership. In addition, Hrfyndal-Hyrshmn index (HHI) is used for calculation of ownership concentration ratio. Cost of capital is considered as dependent variable. Finally, the hypotheses are tested using Multivariate Analysis of Variance (Manova). Based on the research results, governmental and private institutional ownership increase average cost of capital in levered companies more than capitalized companies and private individual ownership results in reduction of average cost of capital in levered companies more than capitalized companies. Also, based on the research results, concentration of ownership reduces of cost of capital in capitalized companies more than levered companies, however, diffused ownership increases average cost of capital in capitalized companies than levered companies.