Trichoderma reesei strains 30911,40358 and 40359 were used in this study.Nine factors which can affect the yield of cellulase produced by Trichoderma Reesei were designed.The results showed that the optimal microcrystalline cellulose and wheat bran concentration were 20 g·L-1 and 80 g·L-1,respectively,the optimal proportion of microcrystalline cellulose and wheat bran was 1:4,the concentration of inoculated spore was 1×107 ·mL-1,the optimal culture temperature was 28-30 ℃,pH 5.5,the optimal culture time was...