Several strains of yeasts showing strong and weak fermentation abilities on isomaltose and isomaltotriose were separated from Kyokai No.7 yeasts and general characteristics including color formation in TTC media of these yeasts and ingredients of sakes produced by using them were examined. Since glucose concentration in moromi was extremely high, the sakes obtained showed no difference in isomaltose and isomaltotriose contents. The acidity of TTC Pink strains in isomaltose and isomaltotriose media was higher than that of Red strains. This difference was caused by the difference in malic acid contents. With respect to aroma ingredients, iso-amyl alcohol content of the Red strain did not differ from that of the Pink strain, while the iso-amyl acetate content and isoamyl acetate/iso-amyl alcohol ratio of the Red strain were somewhat higher than those of the Pink strain.