Purpose: This study was performed to evaluate anti-thrombotic effect of Jogantanggagambang extract (JGTG). Methods: Blood flow rate through the regular volume of glass tube after the blood was diluted five times with ACD solution. Antithrombotic effect was calculated as a percentage of the experimental animal figure protected from the paralysis of hind legs or death of the mouse that was caused from the administration of platelet aggregation regent. Results: 1. JGTG inhibited the platelet aggregation induced by ADP, epinephrine, collagen and arachidonic acid as compared with the control group. 2. JGTG inhibited pulmonary embolism induced by collagen and epinephrine (inhibitory rate is 37.5%). 3. JGTG increased platelet number and fibrinogen amount significantly and also JGTG shortened PT and APTT significantly as compared with the control group in thrombus model induced by dextran. 4. JGTG increased blood flow rate significantly as compared with the control group in vivo. Conclusion: These results suggest that JGTG can be used for treating various female diseases caused by thrombosis.