This article is devoted to the research of the phenomenon of megaclusters in economic system and the evolution of the notion of megaclusters in the Russian and foreign science and practice. The author reveals the reasons and conditions of the formation of clusters and formulates the criteria of cluster classification. The article gives the examples of the existing national, international and transnational megaclusters in Europian Union and the points out the cases of forming megaclusters in Russia. In conclusion the author proves the advantages of the megacluster integration for both the members of the cluster and the economic system of the region and the whole country.
Keywords: megaeconomy, global economy, megacluster, integration, national megaclusters, international megaclusters, transnational megaclusters