Objective:To investigate the effects of Qushuanling Capsule(祛栓灵胶囊,QSLC) on thrombus formation and platelet aggregation in rats.Methods:Arteriovenous bypass,venous thrombosis,and middle cerebral artery thrombosis models were used in rats to investigate the anti-thrombotic effects of QSLC,a compound of nine Chinese herbs.The platelet aggregation induced by adenosine diphosphate(ADP),thrombin or arachidonic acid(AA),as well as the contents of thromboxane B_2(TXB_2) and 6-keto-prostaglandin F1α(6-keto-PGF1α) in rat plasma and aortic walls,were determined to investigate the possible mechanisms of the anti-thrombotic effects of QSLC.Results:After oral administration with QSLC for 7 days,arteriovenous bypass thrombosis was obviously suppressed compared with the model group,venous thrombosis was also obviously suppressed,rat behaviors were obviously improved,and brain infarct size as well as water content were also reduced.The platelet aggregation induced by ADP or thrombin was inhibited by QSLC,but the drug had no effect on AA-induced platelet aggregation and content of TXB_2 and 6-keto-PGF1αin plasma and the aortic wall.Conclusion:These results suggest that QSLC can be used in the prevention and treatment of thrombotic diseases,and that its mechanism of action may be related to inhibition of platelet aggregation. Objective: To investigate the effects of Qushuanling Capsule (QSLC) on thrombus formation and platelet aggregation in rats. Methods: Arteriovenous bypass, venous thrombosis, and middle cerebral artery thrombosis models were used in rats to investigate the anti-thrombotic effects of QSLC, a compound of nine Chinese herbs.The platelet aggregation induced by adenosine diphosphate (ADP), thrombin or arachidonic acid (AA), as well as the contents of thromboxane B_2 (TXB_2) and 6-keto-prostaglandin F1α -keto-PGF1α) in rat plasma and aortic walls, were determined to investigate the possible mechanisms of the anti-thrombotic effects of QSLC. Results: After oral administration with QSLC for 7 days, arteriovenous bypass thrombosis was obviously suppressed with the model group , venous thrombosis was also obviously suppressed, rat behaviors were significantly improved, and brain infarct size as well as water content were also reduced. The platelet aggregation induced by ADP or thrombin was inh ibited by QSLC, but the drug had no effect on AA-induced platelet aggregation and content of TXB_2 and 6-keto-PGF1 αin plasma and the aortic wall. Conlusion: These results suggest that QSLC can be used in the prevention and treatment of thrombotic diseases , and that that mechanism of action may be related to inhibition of platelet aggregation.