Cultural conditions and carbon sources affecting the productivity of cellulolytic enzymes of Pleurotus ostreatus 201 were examined in synthetic media. The optimum cultural temperature and initial pH for the production of enzymes were $25^{circ}C$ and 5.5 in avicelase, and 3$0^{circ}C$ and 5.0 In CMCase, and 3$0^{circ}C$ and 6.5 in B-glucosidase. Among carbon sources, cellulose powder was the best for the production of avicelase, and Na-CMC for CMCase, and cellobiose for $eta$-glucosidase. The optimum concentration of cellulose powder was 1.0% (w/v), and glucose depressed the production of enzymes remarkably.