Enzymatic hydrolysis of cellulosic substances in raw sludge of municipal sewage treatment process was investigated with a view to producing reducing sugar and fermenting ethanol. The raw sludge derived from primary sedimentation tank whose concentration was in the range from 2 to 5% was pretreated with sterilizing at 121°C for 5 minutes, and hydrolyzed to monosaccharides by CMCase and β-glucosidase. The optimal conditions of enzymatic incubation for producing reducing sugar were as follows; pH; about 5, mixing ratio of β-glucosidase/CMCase; around 4, pretreatment of raw sludge by protease; about 500mg/l. Enzymatic hydrolysates (0.2% glucose) were converted to 0.1% ethanol by Saccharomyces cerevisiae. Trichoderma viride was incubated with CM-cellulose in order to produce cellulase. The maximum enzymatic activities toward CM-cellulose and β-glucosidase were about 5 and 2.5 units (μmol reducing sugar as glucose/min./ml), respectively.