This paper examines the impact of the corporate ownership structure on product diversification and international behavior, and the effect of product and international diversification on firm value. Following La Porta , Lopez-de-Silanes, and Shleifer (1999), we measure the magnitude of agency problem with the deviation of controlling shareholder’s voting rights from cash flow rights. We find that product diversification is significantly and positive related to the degree of the agency problem. Secondly, when the degree of this deviation is increasing, the international behavior is significantly and negatively related. Furthermore, we also find results suggesting that when the degree of this deviation is decreasing, the firm value of product and international diversification is better.