Fibrin clots remained in blood vessels can be one of the serious factor caused cardiovascular disease, such as ischemia, infarction and necrosis The development of an antithrombotic and thrombolysis solvent is necessary to prevent and treat these diseases. In this study, the fibirinolytic protease was prepared from the maggots of Protaetia brevitarsis using ammonium sulfate fractionation and desalting column. The optimum pH and temperature for the enzyme activity were pH 9.0 and $50^{circ}C$, respectively. The enzyme activity was relatively stable at pH 7.0-9.0 and temperature below $60^{circ}C$. The activity of the enzyme was strongly inhibited by phenylmethanesulfonyl fluoride. And the activity of the enzyme was inhibited by $Ca^{2+};and;Zn^{2+}$, but it was not by $Mg^{2+};and;Fe^{2+}$ ions. In these experimental results, we have speculated that the enzyme derived from maggots of Protaetia hrevitarsis is a serine protease with a strong fibrinolytic activity.