It is possible to provide lactic acid bacteria growth-promoting agent that does not interfere with the flavor of food, preservatives, etc.. After the solution was prepared so that 0.01 to 10 degrees Brix water extract of rice koji, and cultured by inoculation of lactic acid bacteria, powdered rice koji extract composition obtained by drying.食品の風味を阻害しない乳酸菌増殖促進剤、防腐剤等を提供すること。米麹の水抽出物をブリックス度0.01~10度になるように調製した液に、乳酸菌を植菌して培養した後、乾燥して得られる粉末米麹抽出組成物。