Propolis, a natural resinous compound collected from honey bees, contains many biochemical constituents and has been used for traditional medicines as early as 300 B .C. Recently, it has been reported to possess many biological activities such as antibacterial, antiviral, fungicidal, local anaesthetic, immunostimulating, antiinflammatory and free radical scavenging properties. To investigate activities of chrysin, one of propolis effective compounds for blood coagulation system was injected endotoxin (4000 EU/kg, i.v.) in rats at 1 hr after administered chrysin (20 mg/kg, p.o.). This study was resulted that chrysin has antiplatelet aggregation activity in vitro, delay of blood clotting time and prothrombin time, and reduction of fibrinogen and FDP in vivo. Chrysin has increased SOD activity, GSH content and GST activity, and decreased MDA content in liver. The result suggests that the antithrombosis effect of chrysin is suppressive activity for a blood coagulation system and antioxidative activity.