Abstract: Objective: To investigate the influence of Ginkgo Biloba Extract on neural cell apoptosis and urtra micro-structure of neural cells in cerebral ischemic penumbra after cerebral ischemia/reperfusion in rats.Methods: Thirty male Wister rats were randomly divided into sham-operation group(n=6),control group(n=6) and treatment group(n=6).The treatment group were injected intraperitoneally Ginkgo Biloba Extract 761(20 mg/kg) before and after middle cerebral artery occlusion;the sham-operation group and control group were injected normal saline(20 mg/kg).Animal models were established by middle cerebral artery occlusion.The number of nerual cell apoptosis was measured by thymidine/deoxythymidine mediated dexoy UTP-biotin nick and labeling(TUNEL),and the changes of ultra micro-structure of neural cells were observed by electromicroscope.Results: The number of neural cell apoptosis was 21.2±3.8 in control group after ischemia 90 min/reperfusion 12 h,versus 9.1±2.3 in Ginkgo Biloba Extract-treated group after ischemia 90 min/reperfusion 12 h,the difference was significant(P<0.01).The neuron apoptotic cells were observed by their fragmented nuclei condensed chromatin,fragmented or condensed cytoplasm and floccule of mitochondrion in the control group after ischemia 90 min/reperfusion 12 h;whereas the distribution of chromatin was well-proportioned,and normal mitochondrion and other organelle were observed in the Ginkgo Biloba Extract-treated group.Conclusions: As platelet-activating factor receptor antagonists,Ginkgo Biloba Extract has remarkable neuroprotective effect.