Abstract: The profitability of each and every business in a supply chain dealing in windfall profit goods relates closely consumer demand, and the service for goods rejection thus becomes one of the main competitive strategies of a business. Profit distribution is not only the basis of the cooperation between businesses in a supply chain, but an incentive. So, aiming at maximizing the gross profit and profit distribution, the cooperative relation between suppliers and retailers in a closed-loop supply chain in random demand and profit sharing among them are modelled. Three main characters of the model considering windfall profit product were derived. A conclusion is drawn that it is reasonable to a certain extent if a business as a node in the supply chain shares the gross profit with others in accordance to its contribution rate to the whole supply chain.