Utilizing data from 2007 to 2012 issued publicly by the listed companies from board and small board on the Shenzhen Stock Exchange, and using information disclosure evaluation results released by the Shenzhen Stock Exchange as a proxy variable of quality of information disclosure, this paper makes an empirical analysis on the relationship among political association, quality of information disclosure and cost of debt financing. The results show that improving the quality of corporate information disclosure can significantly reduce debt financing costs; the existence of political association weakens the correlation between quality of information disclosure and cost of debt financing.