The water extract of the crude high-protein (68.80%)-containing dry powder of Lumbricus rubellus (USA) was found to contain cellulase, chitinase, protease and amylase. Cellulase activity was present at high levels (940 units/ml) and prompted comparative studies with cellulase from the culture filtrate of the cellulase-rich Trichoderma viride BRC-25, which was present at 2390 units/ml. A partial purification of the cellulase from both these sources by acetone precipitation followed by ammonium sulphate precipitation at different saturation levels was carried out: 40-80% ammonium sulphate precipitates of both sources had an optimum PH of 6 and temperature of 37 degrees C. Filter paper was the best substrate for both the enzymes. The Km for 40-80% ammonium sulphate fraction for L. rubellus (USA) and T. viride BRC-25 enzymes were 9 and 6.75 mg/ml, respectively.