在市场经济中,反垄断法是一项基础性法律。本文运用经济学的理论和方法对反垄断法中的垄断是否适度的问题进行了分析,提出了垄断与有效竞争相容时就是垄断适度的观点。并对反垄断法中垄断的法律界定和具体实体制度进行了经济分析,最后对我国《反垄断法》提出了有关实施和完善的建议。 In a market economy, antitrust law is a basic law. In this paper, the theory and method of economics are used to analyze whether the monopoly in the antitrust law is appropriate or not. It is put forward that monopoly is a moderate monopoly when it is compatible with effective competition. At the same time, the author analyzes the legal definition of monopoly and the specific entity system in antitrust law. At last, it puts forward some advice on the implementation and improvement of China’s “antitrust law.”