Purpose. The study of the process of transformation of state-legal phenomena, as phenomena that exist and develop in accordance with the patterns inherent in the entire system of public relations. The task was to identify the reasons for the need to transform some state-legal phenomena, as well as the forms in which this process can take place. Methodology: as a system of methods, the application of which was justified by the provisions and conclusions contained in the article, formal legal; logical methods and the method of systematic analysis of legal phenomena were used. Conclusions. The authors, on the one hand, highlight stability and sustainability as integral characteristics of the state and law, and on the other hand, emphasize the fact that in this area of public relations there is a constant development, transformation of its substantial part. The characteristic of transformation is given in relation to the peculiarities of a number of state-legal relations. The place of transformation in the system of social changes is shown, the peculiarities of the transformation of definitions, legal structures and the content of state legal institutions are highlighted. Scientific and practical relevance. The interrelation of the process of development of state-legal phenomena with the processes taking place in public life in general is shown.