In this study, a strain of cellulolytic bacterium named N-6 was isolated from lake Huguang Maar. Phylogenetic analysis based on a partial 16s rDNA sequence showed that the strain was Bacillus cereus. Extracellular cellulase produced by the strain Bacillus.cereus N-6 exhibits optimum activity around pH 8.0 at 50°C and has good pH tolerance in the range of 6-9.