Objective: To study the effect of grape procyanidin (GPC) on N-nitroso compounds-induced expression of TNF- mRNA and TGF-?1 mRNA in hepatic cells. Methods: NaNO2 was infused into Wistar rats by 50 mg/kg bw to induce mutation. GPC was infused by 100mg/kg bw and 10mg/kg bw respectively through mouth into the rats of two experimental groups. After 8 w situ hybridization was applied to measure the expression level of TNF-?mRNA and TGF-?1 mRNA in hepatic cells. Results: The expression rate of TNF-醡RNA and TGF-?1 mRNA of the hepatic cells in positive control group was 30.23 % and 19.47 % respectively, while that of high-dose GPC group was 11.94 % and 6.96 % respectively .The differences were statistically significant (P