From the perspective of stakeholders with the help of organizational cost theory, this paper discusses the direct impact of company size on stakeholders of the corporate social responsibility. Introducing social expectation as an intermediate variable, this paper analyzes the impact of different company sized on the amount of input in different stakeholders. Referring to the corporate social responsibility report data of 384 listed company in China’s manufacturing industry, this paper Using SmartPLS software to constructs a structural equation model to make an empirical analysis. The research indicates that company size has a significant positive impact on the company’s stakeholders except the employees; Under the mediating effect of social expectation, company size also has a positive impact on the environmental problem and the community problems, and social expectation plays a full role as a intermediary. The results of this paper will help enterprises to formulate reasonable schemes in the process of fulfilling their social responsibilities in line with their own size;and conducive to the Government in the development of social responsibility-related policies, the scale of the enterprise will be considered an important reference.