A new strain of cellulolytic fungus is isolated from soil, when grown on cellulose doubleplate, the velocity of growth is rapid and the result of degradation of cellulose is good. Themorphological and physiological properties of this strain are studied. According to these, thestrain is identified as Penicillium frequentans Westling. In this base, the medium componentsof the optimal liquid state fermentation, the purification of cellulase from this strain and thephysiological propertise of the purified cellu...