Abstract: It was reported that there were rich fibrinolytic substances in the tissue of earthworm Eisenia foelide and this was also verified in our previous work after its purification and in vitro study of its fibrinolytic activities by various methods. So far,we have studied the fibrinolytic extracts of earthworm for several years,and we have established certain procedures of purification. In this article,we studied the pharmacological effects of this extract on the aggregation of platelets of animals. The extract showed prominent anti-platelet aggregation effect after its oral administration in vitro and in vivo. The results showed that this fibrinolytic extract has anti-coagulation effect. And it is potential to be studied further,and perhaps, it may be developed into a new kind of drug to treat and to prevent the thrombotic diseases.

Key words: earthworm, platelet aggregation, experimental thrombosis