During the years of profound institutional transformations of the post-socialist period in Ukraine, the problems of socio-economic development of rural areas have become significantly aggravated. In these conditions, the most urgent need is the modernization of the rural development management system and the transition to a rural-preserving model for the development of agrarian business. The paper emphasizes that such modernization requires a substantial deepening and expansion of its theoretical and methodological basis. In this context, the role of socioeconomics as an interdisciplinary scientific direction, which contributes to a better understanding of the economic and social aspects of rural development and their interrelations, has been noted. The essence, genesis, conceptual foundations and peculiarities of the practical implementation of the socioeconomic approach to modernization of the rural development management system in the conditions of decentralization of authority and the reform of local self-government are considered. It is noted that the approval of the socioeconomic approach in the management of rural development is fully consistent with the general trends of post-nonclassical development of science, one of the decisive features of which is the rapid growth of interest in the study of the interaction of complex systems of different nature and the processes of their self-organization. The following key directions of modernization of the rural development management system are provided in the paper: modernization of the management system for economic component of rural development; formation of an effective system of management of social (socio-demographic) processes that would be aimed at increasing the well-being of rural residents; system optimization of the management institutes and structures for solving a complex of administrative tasks at the state (national), regional and municipal levels. There is a special emphasis on the need to intensify the processes of self-organization of local communities through wider use of social innovations.