Problems of regional distribution and sustainable and balanced socio-economic development of Ukraine’s regions are urgent at the present stage of the state establishing as an equal member of the international community. Thus, the development of the country and its regions in terms of transition to a market economy and economic and political crisis brought about the emergence of many problems. The lack of an effective regional policy and organizational and economic mechanism of balanced regional development as well as the presence of depressive regions and the problems of structural transformation of old industrial regions led to a rather radical differentiation of Ukraine’s regions by economic and social development. Thus, the purpose of the article is to study the systemic and structural transformation methodological maintenance in regional economic and socio-economic systems and to rationalize the approach to forming of organizational and economic mechanism of a region’s sustainable development. In our work we used the traditional and special methods of research, including: historical and logical method, method of abstraction and analogy, and system analysis methods. The current stage of development of Ukraine’s economy is characterized by the search for new forms and methods of management of national economy and its economic activities. New approaches focused on the need for transformation of regional economic complexes in order to achieve balanced development and address the challenges of regional and sectoral organization of production and raising living standards are formed to replace traditional ones, justified in the past, but now ineffective. The article reviews the transformation processes of socio – economic system. The existing conceptual interpretation of the term «region» has been considered. The influence of globalization and regionalization on the development of socio – economic systems has been considered. The necessity of developing new approaches to economic development and balanced system transformation based on the experience of industrialized countries has been stressed. Also, the article studies the necessity to form the organizational and economic mechanism for sustainable development of the region and describes the current trends of the economic system in terms of decentralization of power in Ukraine. So, complex interdisciplinary nature of regional policy, contact and interaction of interests of different regions and sectors of society and regional passivity on changes require scientific support for a balanced, comprehensive justification of decisions that should determine the fate of regional development. Errors in the choice of development strategy of the region, the structure of its economy and use of resources will be more costly for society and population of the region than a mistake in choosing the industrial technology and sector of production. Thus, the article emphasizes the need to develop complex models of individual structural transformation of regional economic systems in Ukraine preserving regionalization trends and taking into account the process of balanced regional development and globalization.Рубрика: Регіональна політика і територіальний розвиток 

region, socio-economic system, globalization, regionalization, sustainable development, decentralization