Based on trust perspective, indirectly measuring the trust degree between enterprises via the business credit model between the corporation and its supplier, and measuring CSR performance via whether to disclose CSR report and the quality of information, this paper makes an empirical test on the role of the CSR improving the trust degree of the corporation. The study finds that the commercial credit costs of the corporation which have disclosed CSR are lower than that not disclosed; The higher the quality of CSR report, the lower costs of commercial credit; There exists a substitution relationship between the level of protection of the legitimate interests of the producers and the influence of the quality of CSR on the commercial credit costs, that is, in the areas with the lower level of protection of the legitimate interests of the producers, the quality of CSR will make greater negative influence on the commercial credit costs.