Objective: To study the expression and effect of macrophage inflammatory protein2(MIP2) in liver injury induced by ischemia/reperfusion(I/R). Methods: Thirtytwo rats were randomly divided into 4 groups(8 rats in each group):false operation (control) group and 3, 9, 24 hours reperfusion group.The expression of MIP2 mRNA in hepatic tissue, MIP2 protein in plasma, the neutrophil infiltration in liver tissue and serum ALT were measured. Results: The expression of MIP2 mRNA in the ischemic tissue was significantly higher than that in nonischemic tissue (P<0.01), and was significantly higher in 9 hours reperfusion group than that in 3 hours reperfusion group (P<0.01); significantly higher in 24 hours reperfusion group than that in 9 hours reperfusion group (P<0.01). The level of plasma MIP2 protein, the neutrophil infiltration in liver, the degree of liver injury had the similar changs of MIP2 mRNA.The expression of MIP2 mRNA in liver ischemia tissue and the level of plasma MIP2 protein had positive correlation with neutrophil infiltration in liver tissue(P<0.01) . Conclusions :The results suggeste that MIP2, one of the neutrophil chemotactic factors, plays an important role in the liver injury induced by I/R in rats.