The paper characterizes the nature of public regional policy in terms of strengthening of competitiveness and economic security in conditions of decentralization reform. It reveals the problems of institutional background of administrative and territorial reform and shows the threats to economic security of territorial communities. Methodical approaches to organization of monitoring of regional competitiveness and economic security parameters are outlined. The paper argues that suggested estimation indicators can become the ground for assessment of competitiveness and economic security condition in the regions, for detecting of bottlenecks and weaknesses and for elimination of threats. Main threats to realization of competitive advantages and maintaining of economic security in Ukrainian territorial communities are presented and a set of measures to implement efficient regional policy of economy competitiveness increase and economic security maintenance in territorial communities is suggested. The paper provides evidence that reforming of regional development policy should secure: transition from a “single center” policy to consideration of multi-hierarchy interests of economic entities at regional level based on the principle of vertical and horizontal coordination of measures of regional development stimulation and regional security strengthening; complex regulating impact based on the use of hybrid tools and mechanisms of regional development and security stimulation. The paper confirms that the following should become the priorities of such policy in conditions of decentralization: optimization of territorial basics of public authority with distribution of competences of local executive authorities and local governments; improving of regions residents’ life quality, reducing of differentiation by human development index and forming of polycentric system of territorial development; implementation of interregional projects and programs of efficient use of local resources; introduction of criteria of “problem” territories’ assessment in regions as well as efficient mechanisms of public support of interregional integration. Special attention is paid to the fact a region’s economy competitiveness is largely determined not only by its ability to “win” in competition with similar economic systems of the country, but by participation in megaregional groupings as well.