Microbial enzymes catalyzing the degradation of cellulose substances play an important role in food, animal feed, textile, fuel, chemical industries. Cellulase is an inducible enzyme complex involving synergistic action of endoglucanase (Cx), exoglucanase (C1) and cellobiase (CB). It is produced by number of bacteria and fungi. The objectives of this study included; bacterial and fungal production of cellulases, evaluation of the physiological behaviour of cellulase producers under nutritional and environmental conditions. Studies were focused on enzyme extraction, partial purification, kinetics behaviour of the enzyme and physicochemical properties. Using some agricultural wastes and by- products as cheap materials for the cellulase production and using shake flasks, solid state cultivation and bioreactor as a batch culture.