The article highlighted the most common theoretical foundations of the concept of democracy in the context of the Constitution of Ukraine tasks of developing a legal and social state. Made a brief overview of the main points of discussion of theories of democracy as a historical and political perspective, and from the point of view of modern analysis. Particular emphasis is placed on the fact that the study of democratic principles of legal, social state provides for an appeal to: 1) national sovereignty and forms of its realization (directly and representative); 2) the ratio of the majority and minority in the exercise of state power, and 3) separation of state and its controllability; 4) law and human rights in the work of public authorities. Particular attention is paid to problems of national sovereignty, the role of representative democracy for the proper organization of power in the modern state. We investigate the issue of national (political) identity of the people as the substance of a democratic state, the issue of
separation of powers as a guarantee of democratic transformation in tyranny, the value of the rule of law and human rights for the realization of democratic principles.
Keywords: democratic state popular sovereignty, the forms of democracy, separation of powers, human rights