摘要:本文旨在提出一則在模糊環境下，雙占市場最適產量之決策方法。為欲有效地掌握決策變數的模糊性，文中提出以三角形模糊數做為模糊決策變數固定成本與單位變動成本的評估工具。文中應用模糊集合理論，建構雙占市場最適產量決策模式，並應用此模式於雙占航空客運市場。在考慮競爭對手提供的產量決策下，可決定每一航次或每段期間的最適產量，根據最適產量，航空公司可進一步作最適機位及最適航次規劃之決策。 Abstract:In this paper, a new optimum fuzzy output quantity decision analysis of duopoly market is developed. To efficiently handle the fuzziness of decision variables, the linguistic values, subjectively represented by the triangular fuzzy numbers, are utilized to act as the evaluation tool of decision variables such as fixed cost and unit variable cost. This paper will apply fuzzy set theory to construct optimum output quantity decision model based on the goal of pursuit the maximum profits of duopoly market. This model can be applied to duopoly air passenger market, it can decide the optimum output quantity of per airline or per period based on thinking about output quantity of competitor. According to the optimum output quantity of per airline or per period, the airlines can make the decision of planning the optimum seats of aircrafts and optimum flights numbers.