At Peoples' Friendship University of Russia, where the authors work, great attention is paid to studying foreign law, in particular civil and commercial law. Teachers and students conduct scientific research not only of Russian law, but also in the law and law enforcement practice of foreign countries. Antitrust law should effectively ensure the unity of the economic space, the free movement of goods, the freedom of economic activity, the protection of competition, including the prevention and suppression of monopolistic activity. That is why the authors study the concepts of dominance (monopoly), the procedure for its establishment, as well as various types of dominance that can be found on the commodity markets of countries such as the Russian Federation and the USA. Based on the analysis of legislative norms and law enforcement practice, the authors determine the attributes, indicating that the business entity is a monopolist - dominant in the commodity market; reveal differences in the content of this concept in two countries belonging to different legal systems. The authors of the article use the comparative legal research method, which allows identifying the features of the approach in the law of the two countries to determine the dominance of several persons.