AIM: To explore the possible mechanism why drinking Maotai liquor dose not cause hepatic fibrosis. METHODS: After being fed with Maotai for 56 days consecutively, the male SD rats were decollated for detecting the biological indexes, and the livers were harvested to examine the liver indexes and the level of hepatic metallothioneins (MT). Hepatic stellate cells (HSC) proliferation and collagen generation were also observed. RESULTS: Hepatic MT contents were 216.0 ng.g(-1)+/-10.8 ng.g(-1) in the rats of Maotai group and 10.0 ng.g(-1)+/-2.8 ng.g(-1) in the normal control group, which was increased obviously in Maotain group (P<0.05). In the rats with grade CCL(2) poisoning induced by Maotai, hepatic MT content was 304.8 ng.g(-1)+/-12.1 ng.g(-1) whereas in the controls with grade CCL(4) poisoning, it was 126.4 ng.g(-1)+/-4.8 ng.g(-1) (P<0.05). MDA was 102.0 nmol.g(-1)+/-3.4 nmol.g(-1) in Maotai group and 150.8 nmol.g(-1)+/-6.7 nmol.g(-1) in the control group (P<0.05). When both of the groups were suffering from grade CCL(4) poisoning, hepatic MT contents was negatively correlated with MDA (r=-0.8023, n=20, P<0.01). The 570 nmA values of each tube with HSC regeneration at concentrations of 0, 10, 50, 100, and 200 g.L(-1) of Maotai were 0.818, 0.742, 0.736, 0.72, 0.682, and 0.604, respectively. From the concentration of 10 g.L(-1), Maotai began to show obvious inhibitory effects against HSC, and the inhibition was concentration-dependent (P<0.05, P<0.01). Type I collagen contents in HSC were 61.4, 59.9, 50.1, 49.2, 48.7, 34.4 microg.g(-1) at concentrations of 0, 10, 50, 100, and 200 g.L(-1) of Maotai. At the concentration of 100-200 g.L(-1), Maotai had obvious inhibitory effect against the secretion of type I collagen (P<0.05). Gene expression analysis was conducted on cells with Maotai concentrations of 0, 50, 100g.L(-1) respectively and the ash values of beta-actin gene expression were 0.88, 0.74, and 0.59, respectively,suggesting that at the concentration of 100g.L(-1), Maotai could obviously inhibit gene expression of type I procollagen (P<0.05), but the effect was not obvious at the concentration of 50 g.L(-1) (P>0.05). At the concentration of 10 g.L(-1), HSC growth in vitro inhibition rates were 16.4+/-2.3 in Maotai group and -8.4+/-2.3 in the control group (P<0.05). CONCLUSION: Maotai liquor can increase metallothioneins in the liver and inhibit the activation of HSC and the synthesis of collagen in many aspects, which might be the mechanism that Maotai liquor interferes in the hepatic fibrosis.