Abstract: This paper takes the participation of nonstate shareholders in governance as the starting point to research the impact of mixed ownership reform in SOEs on their debt default risk The results show that nonstate shareholders participate in highlevel governance of SOEs can alleviate the policy burden of SOEs and suppress managements selfish behavior，thereby significantly reducing the risk of debt default Further research finds that nonstate shareholders can achieve their governance effects by dispatching directors to participate in board meetings and exercising shareholder rights more effectively，but the above governance effect is influenced by the power of management of SOEs Finally，this effect is more effective in SOEs in better external institutional environments and in locally controlled SOEs 

Key words: state-owned enterprises, debt default risk, mixed ownership reform, non-state shareholders dispatch directors to participate in governance

摘要： 本文以非国有股东参与治理为切入点，研究国有企业混合所有制改革对其债务违约风险的影响。研究发现，非国有股东参与国企高层治理能够在缓解国有企业政策性负担的同时抑制管理层私利行为，从而显著降低债务违约风险。进一步研究发现，非国有股东通过派出董事参与董事会会议、更有效地行使股东权利等方式来实现其治理效应，但是该效应受国企管理层权力的影响。最后，非国有股东派出董事参与治理对债务违约风险的防范作用在外部制度环境较好、地方控制的国有企业中更为突出。

关键词: 国有企业, 债务违约风险, 混合所有制改革, 非国有股东派出董事参与治理