目的　探讨大鼠局灶性脑缺血再灌注Fos蛋白表达的意义及其机制。方法　采用免疫组化法观察Fos蛋白在大鼠局灶性脑缺血再灌注后皮层和基底节区的动态变化。结果　Fos蛋白在大脑中动脉阻断 1h后 ,随再灌注时间延长其分布不同。基底节区持续时间长 ,阳性细胞多 ,而皮层持续时间短 ,阳性细胞少。其中再灌注 90min ,Fos蛋白表达最显著。大脑中动脉供血中心区皮层几无表达。结论　Fos蛋白的表达与神经细胞存活密切相关 ,出现Fos蛋白表达的区域神经元易于耐受缺血性损害而存活 ,可能是神经细胞自我保护机制之一 ,Fos蛋白的表达存在扩散抑制 Objective To investigate the significance and mechanism of Fos protein expression after focal cerebral ischemia-reperfusion in rats. Methods Immunohistochemistry was used to observe the dynamic changes of Fos protein in the cortex and basal ganglia after focal cerebral ischemia-reperfusion in rats. Results Fos protein in the middle cerebral artery blocked 1h, with the reperfusion time extension of its distribution. Long basal ganglia, positive cells and more, while the cortical short duration, fewer positive cells. The reperfusion 90min, Fos protein expression most significant. Middle cerebral artery blood supply in the central cortex few expression. Conclusion The expression of Fos protein is closely related to the survival of nerve cells. The neurons that express Fos protein are easy to survive ischemic damage and may be one of the mechanisms of neuron self-protection. The expression of Fos protein is inhibited by diffusion