As the information asymmetry and credit rationing are existing, SME are difficult to gain bank credit. Trade credit, as one of substitution, gives another access to SME finance. Based on three years panel data (from 2007 to 2009) of 196 small and medium listed companies, this paper establishes the empirical models and examines the effects between inter-corporate relationship and trade credit. It finds that: the effects between inter-corporate relationship and trade credit seems like "U"; participate in the business associations, especially provincial associations, has positive impact to gain trade credit; good reputation also has positive impact to gain trade credit, but vulnerable to the macroeconomic. The conclusions of this paper are as follows: one corporate should keep proper relations with other corporates; pay attention to participating in the business associations, especially the provincial associations; even the macroeconomic's impact are very important, the corporate should also pay more attention to the repletion assets' maintenance.