The article is devoted to the study of the problems of spatial and sectoral development of regions on the basis of interregional interaction. The main scientific research within the framework of the spatial approach carried out since 2000 is presented. It has been shown that the work of domestic modern scientists is focused on finding spatial and sectoral priorities for building effective models of mutually beneficial cooperation between the regions of the country. On the example of the Republic of Buryatia and the Trans-Baikal Territory (as regions with positive economic complementarity), an assessment of the localization coefficient of the type of activity and the per capita production coefficient was carried out. The main problems and threats similar to the analyzed regions are presented, including: relatively low growth rate of the average per capita gross regional product in comparison with the average Russian level; relatively low investment attractiveness and an unfavorable institutional environment; incomplete use of production facilities; and low efficiency of realization of economic potential. Spatial and sectoral priorities have been identified; a model of mutually beneficial interregional interaction between the Republic of Buryatia and the Zabaykalsky Krai was built, ensuring the growth of the economies of integrating regions. It was concluded that the territorial division of the Russian Federation into macro-regions makes it possible to consider all possible vectors of interregional interaction from the standpoint of effective implementation of the synergistic potential of their spatial and sectoral development.