This study investigates the effect of mixed ownership reform on the excess leverage of stateowned enterprises during 2007-2018. We fi nd that the extent and probability of excess leverage of state-owned enterprises are signifi cantly decreased after the mixed ownership reform. Specifi cally, using the data of the top 10 largest shareholders of the SOEs, we sort out the shareholding ratio and types of shareholders, then explore how this two variables affect the excess leverage of the SOEs. All of the information of the SOEs are from Shanghai and Shenzhen stock exchange from 2007 to 2018. In this article, we explore the above relationship from the perspective of shareholding ratio and share type, and we fi nd that as the increase of shareholdings and types of non-state-owned shareholders, the extent and probability of excess leverage of state-owned enterprises decreased significantly. It’s likely that the SOEs’ financing cost has been increased without the help of the government. Or, the entrance of non-SOEs improves the operating effi ciency of SOEs, its internal cash fl ow increased and its demand for external fi nance decreased. So, in the further study , we explore the reason from this two respects. We fi nd that, after the mixed ownership reform, the fi nancing cost and internal cash fl ow of the SOEs have been both increased signifi cantly. The results have confi rmed our speculation and it illustrates that the mixed ownership reform can really play an active role in the de-leverage of SOEs. And it also illustrates that the high leverage of the SOEs was resulted from the intervention of the government in some extent and after the mixed ownership reform, without the help of the government, the SOEs cannot raise debt with a lower rate and the diffi culty of debt fi nancing was enhance, so the size of debt fi nancing was decreased and the ratio of excess leverage was decreased on one hand. On the other hand, the entrance of non-state-owned enterprises can promoting the construction of internal control and corporate governance of the SOEs, thus can promoting the effi ciency of operation and increase the internal cash fl ow, thus can decrease the demand for external fi nancing and can decrease the excess leverage of the SOEs.