Historiography the concept of clusters in the evolution of Economic Thought has been formed for many years. A significant contribution to the development of the concept of cluster was made by foreign and domestic scientists. The article considers scientific works of Ukrainian, Russian and Belarusian scientists, in particular: N.Y. Kalyuzhnova, I.V. Pilipenko, T.O. Kuznetsova, A.A. Tashkinov, M.V. Gryazev, S.A. Vasin, O.Y. Shakhov, Y.А. Sidelnikov, L.V. Dmitriev, G.A. Vinokurov, G.A. Yashev, V.K. Shcherbin, S.A. Vidimov, V.F. Bainev, N.I. Bogdan, S.G. Galuzova and others. For example, N. Kalyuzhnova and I. Pilipenko in their monographs reveal the aspect of cluster functioning, in particular, paying attention to the aspect of geographical agglomeration of firms operating in one or more similar sectors of the national economy. O. Voronov and O. Buryak consider the cluster as an ordered, relatively stable set of specialized enterprises that produce competitive products, taking into account the territorial localization of the economic sector. V.K. Shcherbin defines innovation clusters as complexes of enterprises (industrial companies, research centers, scientific institutions), public administration bodies, trade unions, public organizations based on the territorial concentration of networks of specialized suppliers, main producers and consumers connected by a technological chain. Based on the research conducted by the author, the author gave his own definition of the concept of «regional cluster», which is considered as a set of enterprises of related industries, the key role in the formation of which is played by the resource, historical and economic potential of a particular region. We also carried out a theoretical and methodological analysis of the formation of regional clusters in the context of sustainable development of territories, based on matrix analysis methods. The contribution of Ukrainian, Belarusian and Russian scientists to the theory of cluster economic development was systematized by author, and key features of research were highlighted. The main aspects of the formation of regional clusters are considered, which made it possible to identify the main features of their functioning. The author’s hypothesis was put forward regarding the influence of system, process and situational approaches on the activity of clusters. The analysis made it possible to systematize the impact of the above-mentioned approaches on the activity of clusters depending on the stage of the life cycle. The stages of cluster formation, structural and functional intracluster connections based on process, system and situational approaches are studied, and approaches to the formation of cluster classification features are analyzed.