Abstract: This paper tests the strengthening factors of market timing effect in Chinese stock market by properly selecting sample intervals and introducing strengthening factors. The results show that the changes of regulation and policy have significant impacts on corporate financing structure especially after the share reform is completed. By testing a large number of variables such as investor demand, profitability, solvency and capital structure, the paper finds that market timing effect of listed companies is significantly strengthened when they have enough cash. The result is robust after taking into account the relevant laws and regulations.