Abstract: Objective To establish a mouse model of renal ischemia/reperfusion injury, and investigate the renal ischemia/reperfusion injury, the expression and role of legumain in mice with renal ischemia/reperfusion injury and possible mechanisms. Methods A total of 30 C57BL/6 mice were randomly divided into two groups after right renal resection: an ischemia/reperfusion injury (IRI) group and a control group. The mice were subject to blockage of the left renal pedicle for 45 min followed by reperfusion for various times (1, 6 and 24 h). Then, the levels of serum creatinine and urea nitrogen and morphological changes of each group were observed, while the expression of legumain was examined by immunohistochemistry and western blotting. Results After renal ischemia/reperfusion, the IRI group produced remarkably higher levels of serum creatinine and urea nitrogen than the control group after reperfusion for 1, 6, and 24 h (P<0.05). Compared with the control group, the IRI group presented markedly worsened renal injury which was characterized in necrosis of the renal tubular cells, interstitial edema, and increased infiltration of inflammatory cells, and aggravated as reperfusion extended. The expression of legumainin in the proximal tubule of the IRI group was significantly higher than that in the control group (P<0.01). Conclusions Renal ischemia/reperfusion can lead to decreased renal function, renal tubular damage and higher expression of legumain. The change in the expression of legumain may play an important role in ischemia/reperfusion injury.