As part of the convergence, the national legal systems of a number of states that emerged in the early 90s of the twentieth century acquired features characteristic of the Romano-German legal family, and therefore the fundamental principles of law that are implemented within the development models of these countries have acquired a qualitatively new nature, reflecting the fundamental transformations of the state-political structure. The purpose of the study is to consider the features of the national legal systems of the post-Soviet countries, formed under the influence of integration processes of a legal nature that occurred on the territory of the former republics of the USSR. The objectives of the study are to study the main trends of a state-legal nature, to identify the influence of international law norms on the legislation of new subjects of international relations, as well as to establish the influence of the integration of several states into various interstate associations on national legal systems. Formal-legal, analytical, and historical-legal research methods are used to achieve the results. The study found that the national legal systems of the states that were previously part of the USSR are organically oriented towards regulatory requirements implemented within the framework of international organizations of which they are members, which leads to a certain unification of the regulation of public relations, which does not exclude the preservation of national legal traditions. The process of convergence of the legal systems of individual post-Soviet countries is slow, uneven, not always progressive, but nevertheless lays the foundations for joint activities on several issues that go beyond the jurisdiction of a particular State or require joint efforts for effective solutions.