The monograph proposes the author's methodology, which provides for: consistent implementation of a comprehensive analysis of the development of rural areas according to three models: 1) selection of regions with developed agriculture and the agri-food complex; 2) selection of regions with the most backward rural areas; 3) selection of regions according to the opportunities for developing the local economy, as well as the typology of regions, the formation of agrarian policy for the development of the region depending on the type. The work shows that diversification increases employment and income. The resulting relationship between the level of diversification and the sustainability of agricultural development is direct, i.e. the level of diversification affects the sustainability of agricultural development.