Abstract: The present invention relates to a composition for the prevention and treatment of diabetes mellitus and diabetic complications. The composition includes as an active ingredient, a heat-treated powder or extract of glycine soja with hypoglycemic effects. The heat-treated powder and extract of glycine soja have outstanding hypoglycemic effects and therapeutic effects on diabetic complications. The composition of the present invention is useful as a pharmaceutical or food composition for the prevention and treatment (amelioration) of diabetes mellitus or diabetic complications.