Micro-column, cortex and epidermis of corn stover were used to produce cellulases. The effects of solid-liquid rate (SL), fermentation time (FT), concentration of alkali oxide (AO) and pretreatment time (PT) on reducing sugar contents and filter paper activity (FPA) of the solution in the broth were investigated. Orthogonal tests were performed to optimize the saccharification conditions further. The results showed that the highest contents of reducing sugars were determined for the micro-column, cortex and epidermis of corn stover under the conditions of SL 1∶20/FT 5d/AO 1%/PT 3d, SL 1∶15/FT 5.5d/AO 1%/PT 3.5d and SL 1∶15/FT 5d/ AO 1%/PT 3d, respectively. The contents of reducing sugar reached 15.92%, 12.43% and 5.93%, and the highest saccharification percentages of the lignocelluloses reached 31.84%, 18.65% and 8.9%, respectively under the above conditions. The developing trend of filter paper activity was similar to the concentration of reducing sugar under lower concentrations of reducing sugar. 