Disclosed are a method and a composition for stabilizing a reduced coenzyme Q which is useful as a food, a food with a nutrient function, a food for specified health uses, a nutritional supplement, a nutritional product, a veterinary drug, a beverage, a feeding stuff, a cosmetic, a pharmaceutical product, a therapeutic agent, a prophylactic agent and the like. The method is characterized by allowing a reduced coenzyme Q to coexist with a reduced coenzyme Q and/or a reduced coenzyme Q. The composition comprises a reduced coenzyme Q and a reduced coenzyme Q and/or a reduced coenzyme Q.
