The thrombolytic properties contained in an aqueous of asparagus were investigated using the fibrin plate method, measurement of plasmin-like activity, and enzymogram. Raw and boiled asparagus samples were prepared by freeze-drying and then water extraction. The result showed that all the samples dissolved the fibrin plate, and its action was the highest value in the upper half of a raw asparagus. It is suggested that thrombolytic substances in the raw sample had remarkably plasmin-like activity and not on PA-like activity for its mechanism of action. On the other hand, slight increase in absorbance was confirmed in the boiled sample. As a result of the molecular weight of this substance, a dissolved band was confirmed in all the samples with a molecular weight of less than 6,500. This suggests that thrombolytic substances in asparagus are low molecular weight less than 6,500. More detailed molecular weight estimation needs to be considered after purification.