Abstract. Today, one of the most important, most difficult tasks in Russia is the development, improvement of real, practical constitutionalism. For its successful solution, of great importance is the study, taking into account the historical experience of our country in this area. And it is precisely in this that the relevance of the presented article lies, which is devoted to the analysis of the first domestic constitutional projects that appeared in the second half of the 18th century, the consolidation, regulation of the institutions of constitutionalism in them, their possibility of using, of course, with appropriate amendments in modern conditions. Note that these issues have been and remain in the focus of attention of foreign scientists, for example, D.L. Ransel, S.N. Wittaker, C.S. Lenard, M. Raev, S. Bartolissi. The author’s approach to the very concept of “constitutionalism” as a multilateral phenomenon associated with the real presence of the constitution is presented; practical constitutionalism; theoretical constitutionalism. The characteristic of constitutional drafts, the provisions contained in them, concerning constitutionalism of representatives of various kinds of currents of political and legal thought of the second half of the 18th century, and especially the nobility, enlightenment, and popular movement, is given. Based on the analysis, it is concluded that, first of all, in the Russian constitutional projects of that time, three most important institutes of constitutionalism are fixed – representation, and in this regard, representative democracy, parliamentarism; self management; separation of powers. Their contents are disclosed. Note that all these three institutions are present in modern Russia. But the question of their improvement, real effective functioning remains in demand. First of all, three fundamental research methods were used in the work: dogmatic; historical and legal; comparative legal. The article is of interest to government officials, students, university professors, researchers, all those who are interested in issues of constitutional law of the Russian Federation, the domestic history of the state and law.