Abstract: The 92 strains of cellulose-decomposing microorganisms were isolated from soil with timber plant stacked, ten colonies with distinct red zones were selected from them by congo red agar medium. By measuring the enzyme activity of liquid culture filtrates, A strain （Trichoderma reesei FYFJ928 ）was obtained with higher eellulase activity,and the filter paper enzyme （FPA） was 8.3 IU/mL. T. reesei was cultured in different medium to study the ability of producing cellulase at 28℃ with rotate speed at 200 r/min. The optimum medium was determined as follows： 0.5 % yeast extract, 0.06 % MgSO4, 0.5 % NaH2PO4, 2 % glucose, 2 % corn steep liquor, 0.5 % （NH4）2SO4 and 8 % cellulose powder, the FPA was 15.8 IU/mL under the optimized culture medium after cultured for 6 days.