In this study; a two-stage supply chain structure consisting of a supplier and a retailer has been investigated when the demand variable is a fuzzy parameter. Each of the supply chain members has different goals and wants to optimize their performance. Thus coordination between the supply chain members must be confirmed. According to this coordination, supply chains are classified into centralized and decentralized supply chains. For the centralized and decentralized supply chain models, generalized closed-form solutions of optimal order quantity and supply chain members profit functions are obtained using the expected value function and credibility theory when the demand parameter is a fuzzy variable. Then, in addition to the demand fuzziness, when the wholesale price is also considered as a fuzzy variable, supply chain members and supply chain total profits have been obtained for the decentralized supply chain model. Finally, proposed models are analyzed under numerical examples.