Objective To investigate the changes of caspase-1 expression and its enzymatic activity during acute renal ischemia-reperfusion injury. Methods Mice model of acute renal ischemia-reperfusion injury was established. Serum creatinin (Scr) and blood urea nitrogen (BUN) were measured by an auto-analyzer. Caspase-1 expressed in renal tissue was detected by immunohisto-chemistry, and the enzymatic activity of caspase-1 was measured by a fluorescent microplate reader. Results Scr and BUN were increased significantly in the group of acute renal ischemia-reperfusion injury as compared with those in the control group treated with sham operation. Caspase-1 expression and its activity in renal tissue were also much higher in acute renal ischemia-reperfusion injury model than in the controls. Conclusion The over expression and activation of caspase-1 in renal tissue may play an important role in the pathogenesis of acute renal ischemic-reperfusion injury. Control of the hyperactive downstream cytokine network through the inhibition of caspase-1 activity may be a new strategy for the therapy of acute renal ischemia-reperfusion injury.