The present invention provides a particulate composition wherein an oil component containing reduced coenzyme Q 10 is polydispersed forming a domain in a matrix containing a water-soluble excipient, which simultaneously shows high oxidative stability and high oral absorbability, a production method thereof, and a stabilizing method thereof. It also provides a food, food with nutrient function claims, food for specified health uses, dietary supplement, nutritional product, animal drug, drink, feed, pet food, cosmetic, pharmaceutical product, therapeutic drug, prophylactic drug and the like, which contain the composition.