Nowadays one of the relevant problems of economic development of Ukraine is the excessive increasing of the public debt that has a number of negative consequences for the financial system of the country. The article is devoted to the research of state’s debt sustainability concept. Special attention is paid to the development of an effective system of debt sustainability management. The aim of the article is to study the theoretical bases of the state’s debt sustainability, investigate scientific and methodological approaches to its management, analyze the public debt and debt sustainability of Ukraine. In order to achieve that goal, the following scientific methods were used: analysis and generalization, decomposition analysis, comparison and compilation. The authors analyzed the structure of the debt sustainability management system: objects, subjects, key principles, objectives, methods, instruments, etc. The list of key indicators of debt sustainability was substantiated and the authors compared their normative values in Ukraine and in world practice. Besides, the state and structure of public debt and the ratio of government debt to GDP were scrutinized. The obtained results proved the debt crisis deepening in Ukraine.