In the advanced age, cardiovascular disease is more serious than any other disease. Especially, the thrombus causes the serious disease like apoplexia, carebri and myocardial infarction. Thrombosis is caused by the injury of endothelium and the alterations in normal blood flow. To investigate activities of Carthamus tinctorius L. Semen butanol fraction for blood coagulation system, endotoxin (4000EU/kg) was injected (i..v) to rats at 1hr after administration of Carthamus tinctorius L. Semen butanole fraction (500 mg/kg, p.o.). Carthamus tinctorius L. Semen butanol fraction was found to have antiplatelet activity in vitro. In vivo it showed a delay of blood clotting time, and prothrombin time, and reduction of fibrinogen and FDP It also increased SOD activity, and decreased MDA content. These results suggest that the antithrombosis effect of Carthamus tinctorius L. Semen butanol frac tion results from suppressive activity for a blood coagulation system and antioxidative activity.