Chitinase was induced in rice cell suspension culture with treatment of chitooligosaccharides mixture. Among eleven isozymes found in 10% polysacrylamide gel electropherogram, four isozymes were identified as induced enzymes. Acidic chitinase fraction separated in DEAE-cellulose column chromatography, includes three induced chitinase. while basic fraction contains only one induced isozyme. Treatment of chitooligosaccharides mixture enhanced the contents in both protein and chitinase activity in cell suspension culture media, but increase in chitinase activity was much higher than in protein.