A novel process for producing isomaltose and uses thereof and comprising the steps of contacting saccharides, which have a glucose polymerization degree of at least two and α-1,4 glucosidic linkage as a linkage at the non-reducing end, with an α-isomaltosylglucosaccharide-forming enzyme, in the presence or the absence of α-isomaltosyl-transferring enzyme to form a-isomaltosylglucosaccharides, which have a glucose polymerization degree of at least three, α-1,6 glucosidic linkage as a linkage at the non-reducing end, and α-1,4 glucosidic linkage as a linkage other than the non-reducing end, and/or to form cyclo{→6)-α-D-glucopyranosyl-(1→3)-α-D-glucopyranosyl-(1→6)-α-D-glucopyranosyl-(1→3)-α-D-glucopyranosyl-(1→}; contacting the saccharides so formed with isomaltose-releasing enzyme to release isomaltose; and collecting the released isomaltose; and uses thereof.