The article notes that Ukrainian historians and jurists have the opportunity to study the rich creative heritage and new current aspects of the history of state and law-making in the works of MS Hrushevsky since the time of Gorbachev's "perestroika". Attention is drawn to the fact that Ukrainian historians and legal scientists have the opportunity to study the rich creative heritage and new current aspects of the history of state and law-making in the works of M.S. Hrushevsky. The study proves that modern Ukrainian researchers pay attention to the concept of "national idea", state building of Kyivan Rus, the Cossack Republic of B. Khmelnytsky, the constitutional process of the period of the Ukrainian People's Republic, the organisation of the constitutional process in the works of prominent statesman, which is relevant to this day. It is emphasised that without studying this concept it is impossible to explore not only the history of the Ukrainian People's Republic, but also the history of national statehood. The study places emphasis on the importance of current issues of constitutional reform in Ukraine, making provision for continuity, taking into account the traditions and historical experience of the organisation and functioning of state power, the conceptual foundations of the exercise of constituent power. It is proved that the historical absence of legally regulated composition, competences, and procedures of the General, regimental and hundreds of Cossack councils gave the tsarist government grounds to take over the right to allow or prohibit their convening, recognition or non-recognition of their decisions. Therefore, M. Hrushevsky defined the supremacy of the people and its constituent power as the decisive factor in state formation. Hrushevsky was convinced that the "increased general material standard of living" of the people, spiritual culture, "a certain moral rigor is absolutely necessary for the success, development and firmness of democracy... Only when the state, the community becomes not an empty sign, but a real centre of thought and will, the object of worship, religion, which it was for the ancient Greeks or Romans; only then the Great Ukraine will be built"
Keywords: Kyivan Rus, Cossack Republic, democracy, constituent power, representation, supremacy of the people