This paper investigates whether capital structure is sensitive to the structure of firm ownership based on the theory of agent cost. And we make the positive test using 1494 observations of 498 listed firms on Shanghai and Shenzhen Stock Exchange Market between the years 1999-2001. The results show that the difference of ownership structure leads to different influence on the capital structure. We also find that the ownership structure and capital structure can take rather active position in reducing the friction between the proprietor and the manager and decreasing the agency cost in spite of the particularity of Chinese listed firms.