OBJECTIVETo study the factors influencing the activity of fibrinolytic enzymes from earthworm and to obtain the better way to extract fibrinolytic enzymes as well as keep its optimum activity.

METHOD75% alcohol, 0.9% NaCl and 10% saccharose was used to extract the crude fibrinolytic enzymes from earthworm, the method of urokinase gelose-fibrin plate was used to measure the activity of fibrinolytic enzymes from earthworm. and the method of 3,3'-diaminobezidine tetrahydrochloride colorimetry to was used measure the content of selenium. The method use ts of measuring the content of arsenic was silver diethyldithiocarbamate colorimetry.

RESULTThe fibrinolytin of earthworms reared with cattle soils had higher activity than that reared with garbage. The arsenic in the earthworm's body could improve the activity of earthworm's fibrinolytin. However, the selenium had litter influence on it. Among the three methods of extraction, the 75% alcohol one was the most efficient, the 0.9% NaCl was next, and the 10% saccharose was the lowest. The influence of dialysis on the activity of fibrinolytin was less than that of ultrafiltration, when the earthworm's fibrinolytin enzyme was further sublimated.

CONCLUSIONThe activity of the earthworm's fibrinolytin will be increased earthworm is reared with the fitting baits and when appropriate methods, of extraction and purification are used.