Abstract: The subject of the study is international non-governmental organizations (INGOs), considered as an analytical unit of such a paradigm of international relations research as constructivism. Unlike neorealism and neoliberalism, competing theoretical schools that generally do not leave a place for INGOs in their constructions, constructivism allows for the possibility of participation of such organizations in world politics, giving them the role of conductors of various ideas, principles and agendas that could potentially lead to political changes. Nevertheless, INGOs are not conceptualized by constructivism as some kind of "free" actors whose activities are not limited to anyone. When states finance INGOs, they often set certain tasks for them, delegate certain functions to them, or even openly use them as a means of realizing their international political interests. The research methodology is formed by the works of K. Waltz, J. Mearsheimer, J. Ikenberry, A. Wendt, which serve as the foundation of the leading paradigms in the study of international relations (neorealism, neoliberalism, constructivism). The main conclusions of the completed study can be considered as follows. Neorealism demonstrate a certain indifference to the INGOs. Neorealism views states fighting each other as some kind of "black boxes". Since INGOs are based in a particular state, they find themselves inside this very "black box", not deserving of research attention, unlike the great powers. According to the provisions of neoliberalism, global peace and cooperation are possible only with the spread and development of international institutions, which are initiated and controlled by the leading states, which, therefore, deserve priority research attention. Constructivism, on the contrary, allows for the international political significance of INGOs that participate in the formation of identities, in the promotion of ideas and principles, and in the performance of roles that can initiate political change.