Abstract: Aim To observe the effect of extracts of ginkgo biloba leaves(GbE)on platelet adhesion and thrombosis.Methods The platelet adhesion was assayed by rotating glass-globe method.The thrombogenesis method in artery-vein by pass was applied to observe thrombosis in vivo.The Chandler method was applied to induce thrombosis in vitro.The tail bleeding time was recorded by shearing tail method.Results GbE significantly decreased platelet adherence rate in rabbits,decreased the weight of thrombus produced in artery-vein bypass in rabbits,shortened the length and reduced dry weight of thrombus of rats in vitro,prolonged the tail bleeding time in mice.Conclusion GbE inhibits the platelet adhesion and thrombosis.

Key words: extracts of ginkgo biloba leaves (GbE), platelet adhesion, thrombus