In order to enhance the level of demand information sharing between a retailer and a manufacturer, reduce the impact of “bullwhip effect” on demand amplification, a model of Stackelberg game between a retailer and a manufacturer under the condition that the manufacturer makes the decision of ordering is developed in this paper. Through the model inference, the optimal marketing price of the retailer, the optimal primary production quantity and the optimal wholesale price of the supplier under decentralized decision as well as the optimal primary production quantity and optimal selling price of supply chain under centralized decision are respectively obtained. By numerical analysis, the impact of demand risk under the two decision conditions on the profit of the retailer, the manufacturer and supply chain as well as supply chain efficiency is discussed. Further analysis finds that when there is big market risk, the profit and efficiency of the supply chain can be facilitated if the retailer and the manufacturer choose to comply with the decentralized decision.