The major tempeh manufacturing microbe, Rhizopus oligosporus IFO 32002, could grow well on a wheat-bran medium and produced carboxymethylcellulase( CMCase), β-glucosidase, xylanase, amylase and protease. CMCase showed the highest activity among these enzymes, except for amylase, in the early phase of the culture. The source of CMCase activity was divided into three fractions from a CM-Sephadex column. The main component was purified as a single protein by electrophoresis. The molecular weight of this enzyme was about 40,000, the optimum pH value for the activity being 5.5 and the optimum temperature being 50 ℃ . This enzyme also showed slight activity to α-cellulose, filter paper, and cellophane, in addition to carboxymethylcellulose. The enzyme activity was inhibited by various positive ions.