The dissertation is the first in the national science of Civil Law special complex research of the contents of relationships of obligations under the civil legislation of Ukraine. The simple and complex obligations were distinguished in the dissertation, their definition was provided, as well as the definition of the main/basic obligations. Auxiliary and additional obligations were allocated in the structure of relationships of obligations and their concepts were defined. The expediency of application of the term ""relationships of obligations"" was substantiated, the definition of these relations was formulated and general characteristics of their structure and content were provided. Civil law phenomena that go beyond the concepts of obligations and relationships of obligations were researched. Relationships of obligations were distinguished from adjacent legal categories (agreement/contract, public rights, absolute rights, obligations arising from damage caused due to defects of goods, works, services). The main/basic proprietory and main/basic organizational obligations were singled out, their content, moments of emergence and termination were explored. The legal nature, parties, content, moments of emergence and termination of auxiliary property, auxiliary organizational, organizational-informational and informational obligations, auxiliary mortgage obligations were determined. The contents, moments of emergence and termination of certain types of accessory (additional security) obligations (accessory obligations regarding the payment of the forfeit, suretyship obligations, accessory warranty and deposit obligations) were characterized. The additional obligations of indemnification, indexing of indebtedness and payment of interest were identified, their legal nature, contents, moments of emergence and termination were clarified. The existence of additional obligations that arise after the termination of the main/basic obligations was substantiated, their contents, moments of emergence and termination were characterized. Theoretically substantiated proposals on the improvement of the current civil legislation of Ukraine in the field of regulation of relationships of obligations were formulated.
