Abstract: Different pulp concentration as carbon source for cellulase proc’tuction by Trichoderma reesei was investigated. The best pulp concentration was 12 g/L. After 3 days of cultivation, the filter paper activity, CMCase activity and [3-glucosidase activity were 1.68,0.96 and 0.28 U/mL respectively. Fed-batch manner could significant increase cellulase production by Trichoderma reesei. The fed-batch manner was that initial pulp concentration was 9 g/L and 2 g/L pulp was added to the culture at second, third and fourth day. After 3 days of cultivation, the filter paper activity, CMCase activity and β-glucosidase activity became 2.41,0. 72 and 0.27 U/mL respectively. Compared with batch culture used 15 g/L pulp, the filter paper activity increased 1.8 times.