This paper examined the non-tradable share reform affects ownership structure and figure out how the mechanism relationship between two types of equity agency cost changes. In order to achieve the result, data from listed company is used to analyze the changes of relationship between ownership structure and equity agency cost after non-tradable share reform. The results of the research show non-tradable share reform has a significant impact on the agency costs; after non-tradable share reform, the correlation of ownership concentration and Type I agency cost becomes significantly negative, and the negative relation with Type II agency cost strengthen. On the other hand, the relation between equity restriction and two types of agency costs shift from non-correlations to significantly positive correlations; negative correlation between organization investors and agency costs become weaken.