The article substantiates the theoretical and methodological principles of integration of regional economic systems (CSGs), which means a set of spheres of the regional economy, connected with each other by cooperation, specialization of production, mutual supply of products, orders. The core of these systems is the priority sectors of the economy, the functioning of which causes a multiplier effect in the fields of economic activity associated with them, creating a synergistic effect in the rational use of productive resources and human potential. Delegating functions related to social and economic development, to the grassroots level of management requires the definition of regional economic priorities, which, in essence, form the carrying structure of the CSG. The choice of these priorities is not arbitrary, as there are always deterrent factors that require them to be considered in the process of developing a regional sustainable development strategy. At the same time, creating factors, around which regional economic priorities are formed, operate. In the Transcarpathian region, these are unique natural and human resources that allow the formation of a regional strategy for development involving forest, tourism and recreational spheres, as well as agriculture. By providing deepening of the territorial division of labor, specialization and cooperation of production, integrated economic systems through diversification of production, improvement of organization of management with developed marketing functions create the basis for the integrated use of local resources, the use of low-waste and non-waste, energy and resource-saving technologies, in general, sustainable development of the region.