Objective:To observe the effect of Irbesartan on inflammatory factors in the brain of ischemia-reperfusion rat. Methods:The male SD rats were randomly assigned to sham operated group,ischemia-reperfusion(I/R) group and Irbsartan pretreatment group. The focal I/R model was made by suture occlusion of right middle cerebral artery(MCAO) for 90 min followed by suture retreat which was defined as the beginning of reperfusion. Irbesartan[30 mg/(kg·d)] was administered for 3 weeks before MCAO. After 24 h or 72 h of reperfusion,the neurologic function impairment was evaluated by Longa standard,NF-κB p65 and IκBα protein levels were examined by Western blot technique. Results:① Compared with I/R group,pretreatment with Irbsartan could significantly improve neurologic function (P < 0.05). ② Compared with the sham group,the NF-κB p65 protein was significantly increased after either 24 h or 72 h of reperfusion in I/R group(P < 0.01). Compared with I/R group,however,the NF-κB p65 protein was significantly decreased in Irbsartan pretreatment group(P < 0.05).③ Compared with the sham group,the IκBα protein was significantly increased after 24 h of reperfusion in I/R group(P < 0.05). Compared with I/R group,the IκBα protein was significantly increased in Irbsartan pretreatment group(P < 0.05). Conclusion:Irbesartan can protect brain and may improve the rat neurologic function through enhancing IκBα protein expression and inhibiting NF-κB protein expression in rat brain with ischemia-reperfusion injury.