Abstract: The object is to provide a novel glycosyltransferase and the use thereof, the glycosyltransferase catalyzes transglucosylation of maltotriose units under conditions which can be employed for the processing of foods or the like. Provided is a maltotriosyl transferase which acts on polysaccharides and oligosaccharides having ?-1,4 glucoside bonds, and has activity for transferring maltotriose units to saccharides, the maltotriosyl transferase acting on maltotetraose as substrate to give a ratio between the maltoheptaose production rate and maltotriose production rate of 9:1 to 10:0 at any substrate concentration ranging from 0.67 to 70% (w/v).