In order to identify the impact of changes that have been introduced as a result of decentralization, a study was conducted on the effectiveness of the formation of the revenue side of local budgets in the period before and after the beginning of local government reform. To conduct a comprehensive analysis of changes in the definition of revenues and expenditures of local budgets, the level of the ratio of expenditures made from the local budget to tax revenues has been established. There was a significant increase in the values of the indicator, which means a decrease in the level of tax capacity of local budgets. In the context of the analysis of changes in the composition and structure of local budget revenues, an increase in the differentiation of revenues to general and special funds almost doubled in the period after the changes to the budget and tax legislation. This is evidence of the growing social orientation of budgetary resources and the lack of their focus on economic development of administrative-territorial units of lower levels. The role of basic taxes in ensuring the capacity of territorial communities is determined. The transition to the use of subventions as transfers to local budgets has been noted, which indicates a decrease in the possibility for local governments to independently resolve the issue of directing funds from the provided transfers to the relevant areas. The expediency of determining the relationship of such factors as the number of inhabitants of the community and the level of its financial capacity in connection with the creation at the first stage of formation of united territorial communities as administrative-territorial units with up to 2 thousand people, and and communities with a population of 20 thousand people. As a result, communities with larger populations were found to have greater financial potential. The most effective is the formation of communities with a number of 10-25 thousand people. The reason for the formation of patterns between the number of inhabitants and financial capacity is determined, first, the presence of greater opportunities for business development, the availability of labor resources and the market for products; second, greater potential for sustainable development and infrastructure maintenance and development opportunities in large communities.