Abstract: Objective To observe the effect of simvastatine and fenofibrate on adipose serum triglyceride lipase (ATGL) and TNF-α levels in rats with non-alcoholic fatty acid liver disease (NAFLD). Methods Seventy-eight male SD rats were randomly divided into normal group(n=15) and NAFLD model group(n=63). Rats in normal control group were fed with normal diet and those in NAFLD model group were fed with high-fat diet. Their serum TG and TC levels were measured at the end of 12 weeks. After a rat NAFLD model was established, the rats in NAFLD model group were randomly divided into NAFLD control group, simvastatine treatment group, fenofibrate treatment group, and diet group. The animals were killed and their serum TG, TC, ALT, AST, BUN, Scr, fasting blood glucose (FBG), TNF-α and ATGL levels were measured at the end 16 weeks, their liver index was counted, and their liver pathologic changes were observed. Results The serum TNF-α and ATGL levels were 290±78 and 332±89, 0.69±0.21 and 0.63±0.20, 485±115 and 0.43±0.22, respectively, in simvastatine treatment group, fenofibrate treatment group and NAFLD model group (P< 0.05, P< 0.01). The liver pathological lesions were significantly improved in simvastatine treatment group and fenofibrate treatment group. The serum ATGL and TNF-α levels were significantly higher in diet group than in NAFLD control group(0.52±0.19 vs 0.43±0.22, P< 0.05). The serum TNF-α level was negatively related with the serum ATGL level(r=0.948, P< 0.01). Conclusion Serum ATGL activity is closely correlated with serum TNF-α level in rats with NAFLD. Simvastatine and fenofibrate can increase the ATGL activity by decreasing the serum TNF-α level, thus effectively alleviating NAFLD.