Objective: To investigate the effect of thymosin β4(Tβ4) on mouse hepatic ischemia-reperfusion(IR) injury and its possible mechanism. Methods: One hundred male ICR mice were randomly divided into four groups:sham group,70% IR group,saline group and Tβ4 group respectively. Serum was collected for alanine aminotrasferase(ALT) and aspartate aminotransferase(AST) measurement at 1,3,6,12 and 24 h after reperfusion. Liver tissues were divided into two parts:one part of liver was fixed for HE staining,the other part was maintained in liquid nitrogen for Western blotting and PCR. The expressions of Tβ4,AKT,p-AKT,Bad,p-Bad were performed by Western blotting;the mRNA expressions of TNF-α and IL-6 were detected by PCR. Results: During the process of liver I/R injury,the expression of Tβ4 was decreased at 1,3 h and recovered at 6 h after reperfusion. The levels of ALT and AST in Tβ4 group were lower compared with the 70% IR group and the saline group(P < 0.05),and Tβ4 group also showed alleviated I/R injury as revealed by HE staining. Meanwhile,the expressions of TNF-α and IL-6 were significantly inhibited in Tβ4 group. Furthermore,the Tβ4 group showed elevated phosphorylation levels of AKT(p-AKT) and Bad(p-Bad) at 1,3,6 h after reperfusion. Conclusion: Tβ4 can alleviate hepatic I/R injury through activating AKT-Bad pathway directly and inhibiting the expressions of inflammatory cytokines in mice.