Abstract: OBJECTIVE To investigate astrocyte glial fibrillary acidic protein(GFAP) expression on focal cerebral ischemia/reperfusion rats with pre-infusion of dexmedetomidine. METHODS Middle cerebral artery suture method was used to establish focal cerebral ischemia/reperfusion model. Observation nerve function change and score at cerebral ischemia 2 h and reperfusion 24 h, GFAP protein expression in the dentate gyrus of rats were examined by immunohistochemistry method. RESULTS Ischemia/reperfusion could enhance GFAP expression in dentate gyrus, dexmedetomidine could improve the neurological function injury and reverse GFAP expression in rats significantly(P<0.05). CONCLUSION Pre-application of dexmedetomidine can inhibit the astrocyte GFAP overexpression and play a protective effect against cerebral ischemic injury.