The purpose of this paper is to examine the effect of ownership structure and board characteristics on cost of equity capital. The main feature of this study is that we divide the agency problem into core agency problem and equity agency problem, and we explore the relation between corporate governance and cost of equity capital. Overall, this paper expects to explain corporate governance and can reduce agency problem and the efficient corporate governance can decrease cost of equity capital. The empirical results indicate as follows: First, managerial ownership is negatively related to cost of equity capital and hence supports convergence-of-interest hypothesis. Second, as controlling right deviates from cash flow right, cost of equity capital is getting worse, that is, core agency problems become more serious in the firm. Third, the shares of board directors, institutional ownership and the number of the outside directors have negative relationship with cost of equity capital, but the pledged share ratio of directors and the chief executive officer (CEO) duality have positive relationship with cost of equity capital. Finally, Trade-off Relationship between core agency problem and equity agency problem.