Using Aspergillus niger AN01 as original strain, mutated strain Aspergillus niger AN03 was obtained by N+ implantation. The results showed that activities of acidic protease, cellulase and pectinase of Aspergillus niger were raised from 71.6U/g, 141.7U/g and 264.8U/g to 996.5U/g, 940.4U/g and 906.5U/g respectively. Characteristics of enzymes production in the mutant Aspergillus niger AN03 kept stabile by 5 times subculture. In addition, the optimum conditions for enzymes production of Aspergillus niger AN03 were investigated. The optimum components of medium consisted of bran 105.0g, corn straw 105.0g, bean cake 105.0g, NH4Cl 6.0g, H2O 1000mL. The optimum fermentation condition was incubated for 4d in the condition of pH 5.0 and temperature 30 degrees C.