Abstract: The effects of carbon sources on the preparation of β-glycanases were investigated. The result showed: The filter paper activity,CMCase activity, cellobiase activity and xylanase activity were 1.03 FPIU/mL, 0.54 IU/mL, 0.08 IU/mL and 149.7 IU/mL, respectively, when 15 g/L corncob employed as carbon source by Trichoderma reesei. The poor-xylanase cellulase was synthesized under 15 g/L kraft pulp as carbon source. The poor-cellulase xylanase, which was suitable for biobleaching,was formatted when the T. reesei cultivated in the same concentration of unpurified xylan,and the ratio of xylanase to CMCase was 785.4.