Ginkgo biloba extract (GBE), which contains flavone glycosides and terpenoids, is widely reported to have functions such as to reduce adhesion of blood cells to endothelium, to modify vasomotor and to inhibit activation of platelets and already commonly used as a therapeutic agent for cardiovascular and neurological disorders due to its beneficial effects on health.Though its remarkable antcoagulation activity has been demonstrated, the molecular mechanisms are still unknown.This study was designed to elucidate the molecular basis on which GBE inhibits platelet activation.In the study, GBE inhibited platelet aggregation induced by ADP, collagen and U4 both in platelet rich plasma(pRP) and washed platelet(PPP).In addition, GBE also impaired both the adhesion of platelets to collagen coated surface and platelet spreading on fibrinogen.Furthermore, phosphorylation of Akt was acutely inhibited by treatment with GBE, indicating that it may have its function on platelet via PI(3)K/Akt pathway.