Two types of carboxymethyl cellulases (CMCases, C-I and C-II) from an alkalophilic Cephalosporium sp. RYM-202, were purified to homogeneity by a series of chromatography separations. The hydrolysis patterns revealed that the CMCases were endoenzymes. The optimum pH for C-I was 8.0 and that for C-II was 7.5-9.5. Both enzymes were stable over a wide range of pH and retained more than 80 % of their activities after exposure to pH 11 for 24 h. The CMCases were also stable in the presence of various laundry detergent components, indicating their possible application as an effective additive for laundry detergents.