In recent years, social responsibility has been paid more and more attention by governments and enterprises. in order to pursue their own development, firms lead to some social problems, such as food safety issues, environmental pollution, employee rights protection and so on. In this context, social responsibility has become a hot topic in theoretical and practical research. Domestic scholars research on corporate social responsibility has mainly focused on corporate governance, and it has only done some normal description on taxation which is an important part of social responsibility. There is no empirical way to test the relationship between corporate social responsibility information disclosure and tax avoidance behavior. Finance is the foundation and important pillar of state governance. The scientific taxation system is the guarantee for optimizing the allocation of resources, maintaining market unification, promoting social fairness and realizing national long-term stability. For firms, the tax burden is also an important factor that affecting its value. In recent years, Chinas macroeconomic slowdown, under the dual pressures of local economic growth and financial expenditure corporate tax revenue continued to rise. At the same time, corporate tax avoidance is also more and more common, which makes corporate tax evasion to become an important issue to discuss. Thus, this paper uses the empirical research method to verify the relationship between corporate social responsibility and tax avoidance. In addition, corporate social responsibility helps to improve its reputation, improve the attitude of government, customers and other stakeholders, and then improve market value of the firm. Also corporate tax evasion improve the degree of information asymmetry, and provide the opportunity for managers self-interest behavior, then increase the cost of agency agents and leading to lower corporate value. So, whether the corporate tax avoidance behavior can be the mediation variable between corporate social responsibility and firm value? This is one of the core problems of this paper.The date of our sample comes from the Rankings CSR Ratings and CSMAR database. The descriptive statistics and the basic linear regression model are used to analyze and verify the hypothesis of this paper. The result shows that corporate social responsibility enhances the firm value. Furthermore, the study found that the better the corporate social responsibility, the lower degree of the tax avoidance, and then the higher firm value. In general, corporate tax avoidance behavior plays a intermediary role in corporate social responsibility and corporate value. Namely, through the implementation of social responsibility, firms can reducing corporate tax avoidance and thus enhance the value of the enterprise.This study makes up for the shortness of empirical study on corporate social responsibility and corporate tax avoidance behavior, confirming that the development of corporate social responsibility can promote the tax awareness of enterprises and reduce the tax avoidance behavior. This means that corporate social responsibility is not a simple risk management behavior, but a real recognition of the concept of social responsibility to make it part of the corporate culture, and thus tend to behave consistent with the social responsibility of corporate behavior. This helps to provide the driving force for our government to further promote the development of social responsibility, to improve the institutions of social responsibility. At the same time, the research helps the tax authorities to grasp the focus of tax supervision and examination, and better protect the tax order of our country and guarantee the interests of the state and the public.