PROBLEM TO BE SOLVED: To provide an inexpensive high-safety fermented soybean composition, having different mechanisms of antidiabetic action, acting effectively in the prevention, improvement, and treatment of at least either one of type 1 diabetes and type 2 diabetes, and further having preventive, improvement, or therapeutic effect on the complications of diabetes, and to provide also a production method thereof, antidiabetic composition and food-and-drink.SOLUTION: Provided are a fermented soybean composition containing an extract of the fermented soybean made by fermenting a solid fraction of milled soybean, and a production method of the composition. Also, provided are an antidiabetic composition and food-and-drink containing the fermented soybean composition. In a desirable example, the fermented soybean is fermented by use of at least either one of bacillus natto, Tempeh fungi, lactic acid bacteria, and yeast cell.
