Efficiency of public authorities’ decentralization in Ukraine depends on the coherent reforming, development and activity of three social subsystems: public management, local governance, civil society. Reforming of local governance and authorities’ territorial organization based on decentralization causes new managerial challenges for central and regional authorities and local governments, including the united territorial communities (UTCs), which acquire new much broader competences and stronger financial capacity. The paper aims to define the ways to provide sustainable balanced development of united territorial communities based on the analysis of the dynamics of their forming and the rates of their efficiency. The dynamics of forming of united territorial communities is analyzed. The author reveals that it is stipulated to a great extent by the fact that law provides only for voluntary consolidation, which will further slow the process down and cause some problems. The paper explains the statement that maximum attraction of civil society institutions and business representatives to cooperation on partnership basis is an important way to improve the efficiency of local governance and form the capacity of territorial communities. The author notes that the substantial gap in the efficiency of united territorial communities is stipulated by their initial conditions and the level of available management. The paper proves that achievement of financial capacity for territorial communities is possible through filling the local budgets with revenues from single tax, fuel excise, land fee and other own income rather than solely through individual tax. The priority activity directions of local governments on strengthening of financial stability and independence of local budgets are defined. The role of prediction of changes in the structure of territories’ population in spatial development for securing of sustainable balanced development of united territorial communities is determined.