經濟學廠商理論中，傳統上有許多學者以各種不同的模型來詮譯寡占市場上，廠商與廠商間的競爭行為，猜測變量模型為最主要的型模之一，而廠商間的猜測行為是一種非隨機的不確定性，其概念符合Zadeh(1965)所提出的模糊概念，因此本研究將猜測行為視為機會成本加入傳統成本函數中，而有下列命題： 命題1：對生產差異化產品的廠商而言，它的生產成本較高，所以在市場上該商品應有較高的售價。 命題1.1：廠商如果均生產同質性的商品，此時應該有相同的售價。 命題2：在加入模糊機會成本後，廠商在長期均衡時，最大利潤為零。廠商的生產不再是像古典理論所稱的生產無效率，而是生產有效率的均衡。 命題2.1：而這均衡在長期下是一個獨特的穩定均衡，並且是符合最適技術效率和分配效率。命題 3：偏離均衡產出及均衡價格將是不穩定的均衡。 此時會發生廠商進入或是退出、調整公司規模大小使其合理化。 In the fields of Industrial Economics, there are many scholars illustrated competition behavior of oligopoly market with the matter of interaction. A conjectural model in oligopoly market and conjectural behavior, which was conformed to fuzzy theory by Zadeh(1965), is to include non-stochastic uncertainties. So, in the research regards conjectural behavior as the opportunity cost and imputes the traditional cost function. We conclude the following propositions: Proposition 1: As to manufacturer producing difference products, its production cost is relatively high, so that goods should be sale higher prices in the market. Proposition 1.1:If firm 2 produce the products the same as firm 1, there are the same prices in the market. Proposition 2: After imputing the opportunity cost to the cost function, it is conformed to be profit-maximizing, zero-profit and production-efficient solution in the long run equilibrium . Proposition 2.1: And, it is a stable and unique equilibrium in the long-term with technological and allocational efficiency. Proposition 3: Deviating from equilibrium, the adjustment (the entry or exit) will occur until firms are fully compensated for their technical and conjectural costs.