The ability of different fungi cultivated on cellulose to synthesize extracellular cellulase was examined. The fungus Geotrichum candidum str. 3c was the most active among the fungi tested, including Trichoderma fungi. The formation of cellulolytic enzymes in the culture filtrate of G. candidum occurred, when the entire glucose and the major portion of reducing substances were utilized. The formation of cellulases depended on the content of ammonium ions. The enzyme accumulation reached the highest level at the stationary phase of the culture growth and depended on the inoculum amount. When the inoculum was used as a submerged culture at a concentration of 3%, accumulation of C1-enzyme, endo-(1 leads to 4)beta-glucanases, and beta-glucosidases reached maximum by 44, 52 and 56 hours of cultivation. The fats that are frequently used as a foam catcher inhibited the cellulase formation by the abouve strain. From the filtrate cellulolytic enzymes were isolated via spray drying and precipitation with 3 ethanol volumes to yield 6.5 and 5.0 g/l, respectively. The cellulases when stored at 5 degrees C did not lose their activity for a year and became inactivated by 40-50% in 5 years.