The nature of bank system sustainability is researched. Taking into account a considerable instability of economic development in Ukraine and accelerated changes in the structure of its socio-economic environment, the features of maintaining the sustainable economy development in general and bank system in particular are outlined. In the process of analysis of major parameters of domestic bank system’s functioning the authors confirm that the fall in bank sector activity and its reliability as well as an absence of predicated development trends are among the main reasons of crisis phenomena in economy. The impact of the defined parameters on maintenance of bank system sustainability is determined. Indeed, bank sector is the component of economic system and has a direct impact on real sector, therefore, credit opportunities and restoration of its development paces depend on sustainability of bank system. Domestic bank system had experienced difficulties with maintenance of stability and reliability even before crisis, so the crisis only contributed to existing latent problems. Therefore, one of the major tasks to be solved by regulating authorities is conducting of complex structural reforms based on anti-crisis mechanisms of banks system stability restoration. The nature of bank system’s anti-crisis regulation is defined and its role in conditions of financial instability is revealed. Anti-crisis programs of bank sector development help timely detection, prevention and elimination of risks and crisis phenomena in bank activity. Major activities in terms of anti-crisis regulation of bank system in conditions of global instability are outlined. In order to restore the sustainability of bank system it is necessary to perform strict control for targeted use of refinanced loans, to continue the process of bank institutions’ recapitalization and to raise the level of clients’ deposits protection in terms of change of priorities from the banned early withdrawal of deposits to guaranteeing of repayment of all depositors’ money on part of regulator. These measures will contribute to the country’s overcoming of internal misbalances and minimizing of financial stabilization risks. 

bank system, bank system sustainability, crisis, crisis phenomena, anti-crisis regulation, monetary policy, bank system strategies