In this study a novel fungus, Penicillium ochrochloron ZH1 was isolated from soil and identified by 18S rDNA gene sequence technology. Various process parameters affecting CMCase production were optimized through one factor at a time. Results revealed that maximum enzyme production was obtained when medium was supplemented with 3% rice straw powder, 0.4% ground nut meal as nitrogen source, 0.050% CaCl2, with medium pH of 3.0 and 8% inoculum at 30 A degrees C for 144 h of fermentation period. The purified CMCase had molecular weight of 29.7 kDa determined by SDS-PAGE. CMCase had pH and optima of 5.0 and 40 A degrees C and retained 90% CMCase activity after 3 h at 50 A degrees C. Ca2+ and K+ stimulated CMCase activity while Cu, Co and Ca2+ found to be inhibitors of CMCase. The purified CMCase had V (max) of 18.18 mg/ml/min and K (m) of 18.45 mg/ml for CMC as substrate specificity. [GRAPHICS] .