The purpose of the study is to identify the main trends and factors influencing the development of the theoretical concept of the legal system and possible categories derived from it. The methodological basis of the research is represented by such scientific methods as dialectical, logical, historical, predictive, systemic analysis and content analysis. This made it possible, in view of achievement of the said objective, to analyse the works of Russian and foreign comparativists, both the founders of modern comparative jurisprudence and novice researchers, as well as the materials of scientific conferences on the problem under investigation. The result of the study was the conclusion that the complex nature of the category “legal system” makes it possible to form a holistic picture of legal reality. At the same time, the result of the research depends on the criterion laid as a basis for this concept. The paper also substantiates the fact that presently one may observe a tendency towards a comprehensive understanding of the legal system, towards rejection of the formational approach in favour of the socio-cultural one, with regard for a number of other internal and external factors affecting the formation and functioning of the legal system. The novelty of the study was the conclusion that the concept of the legal system, as well as the categories derived from it, so far represent the basic theoretical function in formulating hypotheses, setting goals and objectives of comparative legal research. At the same time, the authors note that a unified approach to comprehending the essence, typology and classification of legal systems is objectively not possible in the conditions of multiple legal cultures and traditions of legal consciousness, which, ultimately, should be assessed as a positive stimulus for further research.