Urokinase is a highly specific alkaline protease isolated from the urine of healthy men. White powder made by the steps of extraction process of urokinase urine after silica gel adsorption, ammonium sulfate precipitation, filtration, chromatography purification, sterilization, freeze drying,soluble in water, alkaline protease is a highly specific. It is mainly used in the treatment of acute myocardial infarction, acute cerebral thrombosis and cerebral embolism, peripheral arterial and venous thrombosis, central retinal artery and vein thrombosis and other fresh thrombotic occlusive diseases. For formation, peripheral vascular embolism, central retinal vein embolism, acute myocardial infarction and other fresh thromboembolic disease in the treatment of cerebral thrombosis, and renal transplantation, plastic surgery and thrombosis.