Since the Third Plenary Session of the Eighteenth Central Committee of the Communist Party of China in 2013 proposed “actively developing a mixed ownership economy”，the reform of mixed ownership has been steadily advancing and showing a comprehensive speedup. The article combines the policy situation and the practical cases of mixed ownership reform in state-owned enterprises，and analyzes the four key issues related to the mixed ownership reform，such as property rights structure，employee shareholding，governance system and operating mechanism，in order to provide enterprises for the urban development and investment corporations when in-depth advancement of mixed ownership reform.