The activites of seven ginsenosides isolated from Red Ginseng on blood coagulative and fibrinolytic systems closely related to disseminated intravascular coagulation were investigated in in vitro models and compared with those of standard agents (aspirin, heparin and dextran sulphate).Ginsenoside-Rg₂ showed strong inhibitory activity on platelet aggregation induced by three aggregating agents (endotoxin, collagen and arachidonic acid) as compared with aspirin at a concentration of 1.0 mM. Ginsenoside-Ro inhibited the conversion of fibrinogen to fibrin induced by thrombin at concentrations of 0.1 to 1.0 mM. Ginsenoside-Ro, -Rb₁, -Rb₂, -Rc, -Re, -Rg₁ and -Rg₂ may promote the action of urokinase in the fibrinolytic system on the basis of its action on plasminogen-containing fibrin plates.