The main principles of functioning of the deposit insurance system in world practice, its preconditions, defining characteristics, place and role in providing financial security of the country are considered in the article. The basic principles of effective deposit insurance systems, which correspond to the international experience and cover such basic elements as: 1) functioning of formalized with limited coverage of deposit insurance systems; 2) a set of institutions that ensure the effective functioning of deposit insurance systems; 3) deposit insurance system as a link in ensuring the financial security of the country, supported by prudential regulation, supervision and control. The quantitative parameters of deposit insurance in EU countries are analyzed and a single approach to determining the level of financial resources for the deposit insurance system of 0.80% of the volume of insured deposits is established, and its minimum value may be at least 0.50% in individual countries in agreement with EU. The problems of formation and use of financial resources in the domestic deposit guarantee system are outlined. It is substantiated that not only the mechanism of formation of financial resources, but also the level of their use, the amount of insurance coverage and compensation is an important element of the functioning of deposit guarantee systems. It is noted that the deposit insurance system in Ukraine requires reform in the direction of ensuring financial stability and approximation to European practices. Deposit insurance in domestic practice exists indirectly and is based on reservations, depending on the deposit base of banking institutions and the currency of the deposit. The main threats and dangers of the financial security of Ukraine in the area of deposit guarantee were identified, in particular, the insufficiency of the amounts of possible reimbursement at the expense of FGIF funds to the total amount of deposits, the reduction of the total number of depositors of individuals and the need to increase the maximum amount of insurance indemnity towards compliance with the requirements of EU accession. Proposed directions for reforming the deposit guarantee system in Ukraine from security positions are proposed based on adherence to the principles of effective deposit insurance systems defined by the Basel Committee on Banking Supervision and specified by the International Association of Deposit Insurance (IADI).