This paper takes China’s port and shipping companies as an example to analyze the factors related to the proportion of mixed-change in the port industry, and whether it undertakes the social affairs is related to the equity ratio. By the empirical analysis, the non-state-owned shares of shipping companies are higher and the equity is more dispersed. For the more profitable port companies, they have lower intention for mixed reform. However, if the benefits of state-owned companies are too bad, private companies will not be interested. Only when the benefits of state-owned companies are within a certain range, for state-owned companies and private companies are both more willing to carry out mixed reform. The better the social benefits of the company, the better it will be to optimize the trend of the company’s shareholding structure toward the non-state-owned shares.