A composition for enhancing sweetness includes glycan or glycopeptide derived from soy sauce. The composition has excellent sweetness enhancing properties, and particularly has a sweetening effect nearly the same as or better than those of conventional sweeteners and less calories in terms of nutritional characteristics. A sweetener composition includes the composition for enhancing sweetness and a sweetener. A food includes the composition for enhancing sweetness. A method for enhancing sweetness of a food, includes applying the sweetness enhancer composition to the food. The sweetness enhancer of the present invention is a natural product-derived substance, and contains, as an active ingredient, peptide separated from Korean traditional soy sauce aged over a long period of time, and therefore, may solve problems of conventional chemosynthesized sweetness enhancers, for example, side effects, foul taste or the like.
