Abstract: We analyzed the cellulose degradation ability of three kinds of fungi (Penicillium, Mucor and Aspergillus) preserved in the laboratory and optimalized the culture conditions. The transparent ring size of three kinds of fungi training in the congo red medium and in the corncob congo red medium was observed. The cellulase activity was measured of the three fungi cultured in the CMC-Na medium. Single factor and response surface methodology were used to optimize the culture condition. The three kinds of fungi all could produce cellulase. The cellulase activity of Mucor was higher than the other two cultured in the the CMC-Na medium. The optimized conditions were below : pH was 5.0, the shaking speed was 220 r/min，fermentation time was 47 h，fermentation temperature was 35 ℃. The highest CMCase activity was 6.99 U/mL training on the optimized condition. Penicillium, Mucor and Aspergillus produced cellulase and Mucor could degrade corncob.

Key words: Fungi, Cellulase, Culture condition, Optimize