The extraction of the enzyme-humus complexes with protease activity from soil using a series buffered eatractants was studied. It was shown that the extraction of 0.1 M pyrophosphate (pH 7.0) was most efficient. Some characteristics of the extraeted enzyme were different from those of the enzyme measured in soil. The reasults also showed than the K_m value (0.97-1.0mg casein/ml) and optimum temperature (50°-60℃) for the extracted enzyme were lower than those of the enzyme in soil and the V_max value (74.91-75.35 mg tyrosine/g · 24hr.) optimum pH (9) and temperature coefficient (1.93) were higher than those of the enzyme in soil. The effectiveness of the estractants was in order of distilled water<0.1 M phosphate (pH 7.0)-0.3 M KCl-0.01 M EDTA 3 <0.05 M phosphate-citrate (pH 7.0) <0.1 M Na-Pyrosphate (pH 7.0).