Abstract: Abstract: The aim of the study was to provide foundation for the practical application of Aspergillus niger.The optimal culture conditions for the production of cellulases by being liquid fermentation use Aspergillus niger CZ2 . Results indicate that the highest level of cellulase activity is induced in the compound cabon source of wheat bran and corncob, and their optimal ration is 4:3, kalium nitricum are the best nitrogen source, and their optimal ration is1:4, the optimal ratio of C:N is 5:1, and the optimal mass concentration is 4%, the optimal conditions of enzyme were pH 5.8, The optimal culture temperature was 30 ℃, the optimal time is 5d. The activities of cellulose compositions reached the maximal values.In the optimal culture condition,the activities of CMcase and FPAase were 66.41 U/mL, and 61.73 U/mL respectively.