〔Abstract〕 Objective To investigate the protective effect of vitamin D3on alcoholic liver injury in mice. Methods Forty mice were randomly divided into 4 groups: normal Control(Control) group, vitamin D3(VitD3) group, alcohol model(EtOH) group and alcohol + vitamin D3(EtOH+VitD3) group.The mice were fed with the DeCarlialcohol liquid diet to establish alcoholic liver injury model.Serum levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST) and liver index were detected.HE staining was used to observe the pathological changes of liver.The relative expression levels of tumor necrosis factor α(TNF-α),transforming growth factor β(TGF-β),interleukin-6(IL-6) and interleukin-1β(IL-1β) mRNA were detected by quantitative real-time PCR(qRT-PCR).The expressions of nuclear factor-kappa B(NF-κB) p65 and NF-κB p50 in liver were detected by Western blot. Results The serum ALT,AST vitality, liver index and hepatic TNF-α,TGF-β,IL-6 and IL-1β mRNA in EtOH group were significantly higher than those in Control group.EtOH group disorganized hepatocyte and hepatic lobules boundary was not clear, and the hepatocytes showed apparent inflammatory cells infiltration of liver cells and fat cavitation.NF-κB p65 and NF-κB p50 protein expression increased significantly.Compared with EtOH group, the serum ALT,AST vitality, liver index and hepatic TNF-α,TGF-β,IL-6 and IL-1β mRNA in EtOH+VitD3group decreased significantly.The pathological staining results showed that inflammatory cells infiltration and decrease in the number of fat vacuoles, and the liver cells returned to normal liver cell structure.At the same time the NF-κB p65 and NF-κB p50 protein expression level decreased significantly. Conclusion Vitamin D3has a certain protective effect on alcohol-induced liver injury in mice, and its main mechanisms are related to the inhibition of NF-κB pathway and the reduction of inflammatory response.