To explore the influence of the hepatocyte-specific up-regulation of hepatocyte nuclear factor 1α (HNF1α) on mouse hepatic fibrosis induced by carbon tetrachloride (CCl₄). Methods Eighteen C57/B6 male mice were randomly divided into normal group, AAV8-TBG-Ctrl group and AAV8-TBG-HNF1α group, with 6 mice in each group. Mice in the AAV8-TBG-Ctrl and AAV8-TBG-HNF1α groups were intraperitoneally injected with CCl₄ to establish the hepatic fibrosis mouse model, and then the mice in the AAV8-TBG-HNF1α group were injected with AAV8-TBG-HNF1α carrying HNF1α gene under the control of the thyroid-binding globulin (TBG) promoter to specifically up-regulate expression of HNF1α in hepatocytes, while the mice in the AAV8-TBG-Ctrl group were injected with control vector AAV8-TBG. The expression of HNF1α was determined by immunohistochemistry and qPCR. The pathological changes and collagen deposition of liver tissues were detected by hematoxylin-eosin (H-E) staining and sirius red staining, respectively. Immunohistochemistry method was used to detect α-smooth muscle actin (α-SMA), and the expression of fibrosis related genes (typeⅠcollagen α1 chain[COL1A1], α-SMA), epithelial related genes (E-cadherin, Plakoglobin) and mesenchymal related genes (Vimentin, Slug and Twist1) in liver tissues were analyzed by qPCR. The cell proliferation and apoptosis in fibrotic livers were detected by immunohistochemistry and TdT-mediated dUTP Nick-End Labeling (TUNEL) method, respectively. Results Compared with the normal mice, CCl₄ promoted collagen deposition and the expression of α-SMA in livers, and the expression of HNF1α was significantly decreased (P<0.01) in the process of hepatic fibrosis. Compared with the AAV8-TBG-Ctrl group, the expression of COL1A1 and α-SMA in the fibrotic livers in the AAV8-TBG-HNF1α group was significantly decreased (P<0.01). There was no significant difference in the expression of E-cadherin, Vimentin or other Epithelial-mesenchymal transition related genes, or in the cell proliferation and apoptosis between the AAV8-TBG-Ctrl and AAV8-TBG-HNF1α groups (P>0.05). Conclusion Hepatocyte-specific up-regulation of HNF1α significantly improves CCl₄-induced liver fibrosis in mice.