Abstract: ［Abstract］Objective To investigate the effect and the mechanism of parecoxib sodium pretreatment on permeability of blood-brain barrier in a rat model of focal cerebral ischemia-reperfusion injury．Methods　Sixty male SD rats weighing 300g were randomly divided into 5 groups （n＝12 each）: sham operation group （group S）； focal cerebral I/R group（group I/R）；parecoxib sodium 5 mg/kg pretreatment group （group L）；parecoxib sodium7.5mg/kg pretreatment group（group M）；parecoxib sodium 10 mg/kg pretreatment group （group H）. Middle cerebral artery occlusion models were made by reforming Longa suture method in SD rats. Thirty minutes before ischemia， rats in group L， M and H were injected with 5 mg/kg、7.5 mg/kg and 10 mg/kg parecoxib sodium through the internal jugular vein. Group S and group I/R received equal volume of normal saline. ELISA technique was used to determine the content of S100β， TNF-α， IL-1β in Plasma. The changes of cerebral water content and the Evans Blue exudation from brain capillaries were observed. Results Pretreated with parecoxib sodium（5 mg/kg、7.5 mg/kg and 10 mg/kg），the content of S100β，TNF-α，IL-1β in plasma were reduced. The cerebral water content and the EB in brain were reduced. Pretreated with parecoxib sodium 10 mg/kg，Longa scores were reduced. Conclusion　Pretreatment with Parecoxib can protect blood-brain barrier against focal cerebral I/R injury by inhibition of the inflammatory reaction．