Key characteristics of cognitive-neoinstitutional approach to the study of international relations are discussed in the article, and its advantages, apropos, over the structural one. On carrying out comparative analysis of both approaches, the author singles out five such advantages. The first of them, in his opinion, consists in that the cognitive-neoinstitutional approach allows to combine the analysis of actors (states, for instance) and of the system of international relations. The second is that this approach enables the student to theoretically integrate the ideas of a structure and of an actor, of a process and of a structure. As the third advantage of the approach in question the author sees the emphasis laid on constructing a system of international institutions, which gives ample scope for critical estimation of these from the point of view of the culture they reproduce. The fourth advantage is that this approach makes it possible to single out, within the system of international interactions, different subsystems which have their own structure and logic of interaction. Finally, the fifth advantage of the considered approach is that it makes a basis for the analysis of both rational and irrational moments in actors’ behaviour, as well as for combining rational mathematical reconstruction with cultural-anthropological interpretations.