Abstract: The fermentation process and characteristics of the enzyme was studied on a cellulase -producing bacteria isolated from soil. The cellulase -producing process were optimized by orthogonal experiments , the optimal fermentation process was pH4.0, concentration of cassava in the culture solution 25g/L, bacteria inoculation 1.5% (V/V) , shake culture for 56h in 33℃ , the CMCase activity under these conditions achieved 16.982U/mL. The cell concentration attained the highest when the cellulase -producing bacteria was cultured for 24h in broth medium. The characteristics of the enzyme was confirmed, the optimal reaction temperature was 50℃, the optimal pH was 5.0, the optimal time was 60min.