Reducing the level of interregional differentiation is one of the problems in spatial development management according to the Spatial Development Strategy of the Russian Federation. Presence of significant regional imbalances hampers formation of a common economic, social, cultural, and institutional space and lead to a creation of backward territories which lag behind in the development. The focus of public policy measures on the centers of economic growth, with the concentration of financial and labor resources, without solving the problems of backward territories does not bring the expected effect – overall development and well-being. Local effects in the absence of positive changes in other territories result in the increase in imbalances, which limit the overall effectiveness of the public policy. At the same time, a steadily increasing lag may cause a loss of potential of economic growth and thus forms backward territories. The creation of territorial backwardness is a gradual process. Therefore, diagnosing the state of the territory and identifying the signs of increasing depression is an essential issue of public administration. The article presents the main approaches to the definition of territorial backwardness used in the Russia and overseas, it also reviews the determinants of backward territories. Different methods for identification of backwardness in the territorial development have been tested on the basis of the regions of the Russian Far East.
