Based on the data in 53 domestic and overseas listed companies ( in experimental group) and 49 paired companies (in control group) from 2010 to 2011, the paper adopts empirical research method to study the regulatory effect of internal control system on the fulfillment of corporate social responsibility（CSR）. Results show that implementation of internal control system of domestic and overseas listed companies (in experimental group) are better than companies in control group, and the implementation of internal control system has a positive effect on the fulfillment of corporate social responsibility.