This paper considers supply chain models with two competitive manufacturers acting as the leaders and a retailer acting as follower under a fuzzy decision environment. The parameters of demand function and manufacturing cost are treated as fuzzy variables. Two manufacturers are assumed to pursue Cournot competitive behavior and the optimum policy of the expected value and chance-constrained programming models are derived. Finally, a numerical example is provided to illustrate the results of

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... osed models. It is shown that in fuzzy models, the confidence level of the profits for supply chain members affects the final optimal solutions. [12] developed a general equilibrium model of oligopoly retailers competing in price and service under demand uncertainty. Banker et al., [13] and Matsubayashi [14] investigated a price and quality competition under a duopolistic setting, where the consumers' demand was modeled as a linear function of price and quality levels and the cost as a quadratic function of the quality level. Shaffer and Zhang [15] explored the competitive effects of one-to-one promotions in a model with two competing firms where the firms differed in size and consumers had heterogeneous band loyalty. Wu [16] studied the price and service competition between new and remanufactured products in a two-manufacture and one-retailer supply chain. Most of the existing literatures discussed the retailer competition models under a crisp environment, such as a probabilistic market demand and known production cost. However, in real world, especially for new products, the relevant precise date or probabilities are not possible to get due to lack of history data. Moreover, in today's highly competitive market, shorter and shorter product life cycles make the useful statistical data less and less available. Thus, the fuzzy set theory, rather than the traditional probability theory is well suited to the supply chain models problem. In this paper, we will concentrate on the price competition problem between two competitive manufacturers who sell their products to a common retailer under a fuzzy decision environment. We also perform sensitivity analysis of the confidence level of the profits for supply chain members of the models.