当今环境污染日益严重地影响到人类的生产与生活,可持续发展思想的提出使人们对于经济、社会、环境的协调发展有了新的认识.本文研究了开放经济中的Cournot双头垄断市场,分析了产品的消费对环境造成污染的情况下,污染税对市场供应及企业利润的影响,本文讨论了最优污染税如何确定,指出最优污染税取决于市场和企业的实际情况。 Nowadays, the environmental pollution has a serious impact on the production and life of human beings, and the idea of ​​sustainable development has brought people new understanding of the coordinated development of economy, society and environment.This paper studies the Cournot’s duopoly market in the open economy, This paper analyzes how the optimal pollution tax is determined when the consumption of the product is polluting the environment, and points out that the optimal pollution tax depends on the actual situation of the market and the enterprises.