Abstract: AIM: To compare the morphological differences of liver between the two liver fibrosis models induced by dimethylnitrosamine(DMN) and thioacetamide(TAA). METHODS: 0.5% DMN (2 mL/kg; 3 times/week) was injected into the abdominal cavity of SD rats for 4 weeks to create one kind of liver fibrosis model.To create another kind of liver fibrosis models, 0.03% TAA in drinking water was administered orally to SD rats for 9 weeks and then 0.04% TAA was administered orally to SD rats for other 6 weeks. After being treated with DMN or TAA, animals were not treated for 4 weeks for recovery. The morphology of liver was evaluated in two models based on the H&E stain and the severity of liver fibrosis was compared in two models with collagen volume fraction and the protein expression of α-SMA.RESULTS: The mortality of rat in the model induced by DMN was high(30%)but no animal was dead in the model induced by TAA. The success rate in the model induced by DMN were higher than those induced by TAA (P<0.01). And the uniformity of liver fibrosis severity in the model induced by DMN is better than the latter. The two models had the similar collagen volume fractions. The protein expression of α-SMA in the model induced by DMN was higher than that induced by TAA (P<0.01).CONCLUSION: The model induced by DMN is better than that induced by TAA.

Key words: dimethylnitrosamine, thioacetamide, liver fibrosis, morphological difference