This paper empirically tests the impact of market timing on capital structure under different institutional shareholder ratio. The results show the impact of market timing on capital structure is stronger for firms with higher institutional shareholder ratio and weaker for firms with lower institutional shareholder ratio, which indicate that firms with higher institutional shareholder ratio seem to time the issuance of equity more actively, so that the impact of market timing on capital
structure increased. These results are consistent no matter use book leverage or market leverage as the indicator of capital structure.