With sustainable development becoming a globally recognized development trend and China"s goal of "double carbon" being put forward, investors, regulatory authorities and all walks of life attach great importance to enterprises" responsibilities in Environmental, Social and Corporate governance)(ESG). Based on this, this paper takes A-share listed companies from 2011 to 2020 as research samples, investigates the relationship between ESG responsibility performance and stock returns, and considers the regulatory role of marketization process in it. The results show that: (1) The listed companies can significantly improve the stock returns by actively fulfilling ESG responsibilities, and the research conclusion is still valid after considering endogenous problems; (2) The internal mechanism shows that the listed companies" ESG responsibility performance mainly improves the stock returns by attracting investors" attention, enhancing analysts" attention and relaxing corporate financing constraints, and the marketization process plays a moderating role between the listed companies" ESG responsibility performance and stock returns. (3) Further heterogeneity analysis shows that the listed companies" ESG responsibility performance will have different effects on stock returns due to the different property rights and regions. In addition, compared with environmental responsibility (E) and social responsibility (S), governance responsibility (G) has a more significant impact on stock returns. The research conclusion provides empirical evidence for the economic consequences of listed companies" ESG responsibility, and has enlightenment significance for enterprises, investors to pay attention to ESG responsibility performance and the government to improve ESG related policies.