市场垄断是指由于某家或几家厂商控制了市场的供给或需求而产生的垄断。形成市场垄断的原因一是产品的差别化，二是市场准入限制，包括专利限制、进入限制特许经营和外贸限制等。我国垄断行业和行业垄断行为我国的垄断行业，依照垄断的形成过程也可分为自然垄断和市场垄断 Market monopolies refer to monopolies created by one or more firms controlling the supply or demand in the market. First, the reasons for the formation of a market monopoly product differentiation, and second, market access restrictions, including patent restrictions, access restrictions and franchise, and foreign trade restrictions. China's monopoly industries and industry monopoly behavior China's monopoly industries, in accordance with the monopoly formation process can be divided into natural monopoly and market monopoly