Purpose : The Purpose of this research was to investigate the effects of antithrombotic activities of Haenggyonghonghwatang (HGHHT). Methods : Measured the effect which was given to blood flow rate through the regular volume of glass tube after the blood was diluted five times with ACD soulution. 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 is caused from the administration of platelet aggregation regent. Each of the groups consisted in 8 mice, was divided into Normal, Control, and HGHHT. All of these 3 group were supplied a saline solution and after an hour the control group brought the dextran extravasated blood. Also the HGHHT group was dosed to the experimental mice with Oral Zonde one day before the experiment. After that, the mice were abstained from food. And then we gave a measured amount of it before an hour. Finally, it gave rise to dextran extravasated blood as well as the Control group. Results : The results were obtained as follows. HGHHT inhibited platelet aggregation induced by ADP and epinephrine significantly as compared with the control group. HGHHT showed fibrinolytic activity insignificantly as compared with the control group. HGHHT increased blood flow rate significantly as compared with the control group in vitro, but insignificantly as compared with the control group in vivo. HGHHT inhibited pulmonary embolism induced by collagen and epinephrine(inhibitive rate 50%). HGHHT increased number of platelet, fibrinogen amount and shortened prothrombin time, activated partial thromboplastin time significantly as compared with the control group in thrombus model induced by dextran. Conclusion : HGHHT is effective antithrombotic activity from experimental result.