Objective: To observe the effects of total saponin of Aralia Taibaiensis ( TSAT) on the level of oxidative stress in mice with hepatic fibrosis and to explore its relationship with Keapl-Nrf2-ARE signaling pathway. Methods: Forty mice were randomly divided into four groups: the blank control group, model group, high-dose TSAT group, and low-dose TSAT group, with 10 mice in each group. The mice in the blank control group were injected with equal volume olive oil intraperitoneally, while the mice in the other groups were injected with 0. 15 ml/kg CC14 intraperitoneally, twice a week, for 8 weeks. At the same time, mice in the high-dose and low-dose TSAT groups were separately given 400 and 200 mg/kg TSAT suspension by gavage, and the other two groups were given the equal volume of normal saline by gavage, once a day, for 8 weeks. Eight weeks later, the mice were anesthetized and we took the liver tissues. HE staining was used to observe the morphological changes of liver tissues, and Masson staining was used to detect the changes of collagen fibers; hydroxyproline ( HYP) content in the liver tissues was detected by alkali hydrolysis method, malondialdehyde ( MDA) content in the liver tissues by TBA method and superoxide dismutase (SOD) content by WST-1 method; immunohistochemical SABC method was used to detect the protein expression of nuclear factor Erythroid 2-related factor 2 (Nrf2) and heme oxy-genase- 1 ( H0-1) in the liver tissues. Results: ①Compared with the blank control group, in the model group there were inflammatory cells infiltration, and the livers showed hepatocyte degeneration or necrosis; compared with the model group, TSAT significantly attenuated inflammatory cells infiltration and hepatocyte degeneration or necrosis, and the improvement of the high-dose TSAT group was more significant than that of the low-dose TSAT group. ②MASSON staining showed that there was no collagen fibrosis in the blank control group, a large amount of blue collagen deposition was formed in the model group and collagen fibers were suppressed by TSAT in the liver tissues, and the high-dose TSAT was significantly lower than the low-dose TSAT group. ➂Compared with the blank control group, the model group showed that the content of HYP and MDA was enhanced, the SOD activity was reduced in the liver tissues (both P < 0. 01); compared with the model group, TSAT could reduce the content of HYP and MDA and enhance SOD activity ( all P < 0. 01); compared with the low-dose TSAT group, the content of HYP and MDA was reduced, the SOD activity was enhanced in the liver tissues; the high-dose TSAT group was better than the low-dose TSAT group, and the difference was statistically significant ( all P < 0. 05). Compared with the blank control group, the protein expression of Nrf2 and H0-1 was reduced in the model group ( P < 0. 01); compared with the model group, the protein expression of Nrf2 and H0-1 in the TSAT groups was enhanced (both P < 0. 01); compared with the low-dose TSAT group, the expression of Nrf2 and H0-1 was higher in the high-dose TSAT group than in the low-dose TSAT group, and the difference was statistically significant (P < 0. 05). Conclusion: TSAT can reduce collagen synthesis and secretion in the liver tissues of mice by inhibiting the level of oxidative stress, thereby inhibiting hepatic fibrosis; its anti-oxidative stress mechanism may be related to up-regulation of Nrf2 expression in Keapl-Nrf2- ARE pathway and activation of its downstream antioxidant enzyme H0-1. [ABSTRACT FROM AUTHOR]