Abstract:      State-owned enterprise mixed ownership reform is the core of China economic system reform, while the participation of non-state capital has a governance effect on state-owned enterprises, it also affects policy decision-making behavior to a certain extent, then the participation of non-state capital in the mixed ownership reform of state-owned enterprises will also have an impact on the performance of state-owned enterprises′ "mission and inevitable" social responsibility. This paper explores the impact of state-owned enterprises′ mixed ownership structure on corporate social responsibility from two perspectives: burden reduction effect and governance effect. 
   The empirical research results show that: (1) Changes in the dynamic equity structure of state-owned enterprise mixed reform, including diversity, depth, checks and balances, and transfer of control rights, will reduce the level of corporate social responsibility. (2) The mechanism test found the mixed reform of state-owned enterprises can not only alleviate the policy obligations of state-owned enterprises through the burden-reducing effect, thereby having an impact on corporate social responsibility, but also effectively supervise and constrain the management′s behavior to improve the level of corporate social responsibility in order to obtain hidden benefits through the governance effect. (3) In addition, based on the perspective of control hierarchy and governance environment, further research found that compared with state-owned enterprises, the mixed reform of local state-owned enterprises has a more obvious inhibitory effect on the level of corporate social responsibility; regions with a high marketization process and strong government willingness to delegate power have a better governance environment, which can strengthen the impact of the mixed reform of state-owned enterprises on the level of corporate social responsibility. (4) Finally, this paper finds that the mixed reform of state-owned enterprises reduces the level of corporate social responsibility, which is reflected in employees, supply chain and environmental responsibility. And effectively alleviate the negative value effect brought by corporate social responsibility and enhance corporate value. Research believes that the mixed reform of state-owned enterprises should focus on the combination of "quantitative and qualitative changes" in the ownership structure, give full play to the governance efficiency of non-state capital, clarify the nature of the social responsibility of state-owned enterprises, encourage state-owned enterprises to effectively play a role model of corporate social responsibility while improving performance. 
   Our contribution is that: (1) This paper clarifies the path of influence of the mixed reform of state-owned enterprises on corporate social responsibility. (2) Clarify the role of the governance environment in the mixed reform of state-owned enterprises, the nature of state-owned enterprises′ social responsibilities, and the importance of non-state-owned capital′s participation in the ownership structure that influences the decision-making of "quantitative and qualitative changes", it provides certain theoretical and empirical evidence for clarifying the controversy over the effectiveness of the reform of state-owned enterprises and deepening the practice of mixed reform of state-owned enterprises.
  Our research also has some important management implications: (1) The mixed reform of state-owned enterprises not only needs to pay attention to the "quantitative change" of multiple equity, but also the effective "qualitative change" of the deepening, checks and balances and transfer of the shareholding formed by the participation of heterogeneous shareholders, to produce effective checks and balances. In related industries that are not related to the national economy and people′s livelihood, encourage the appropriate transfer of state-owned equity, give full play to the governance role of non-state capital, reduce the "pressure" (policy obligations) of state-owned enterprises, and squeeze out the "water" of corporate social responsibility (agency issue). (2) In the future, the practice of mixed reform should focus on the heterogeneous characteristics of enterprises at different levels of control and the characteristics of the institutional environment. It is necessary to vigorously promote the process of mixed improvement of local state-owned enterprises. (3) Relying on the introduction of non-state-owned capital can optimize the internal governance of enterprises, thereby reducing the level of corporate social responsibility and enhancing corporate value, but the social responsibility and "model role" that state-owned enterprises themselves need to bear cannot be ignored, thereby enhancing corporate value and corporate social responsibility.

Key words:  state-owned enterprise, mixed ownership reform, corporate social responsibility