The article reveals the legal nature, the purpose and system of public authority in modern Russia with Russian multinational people being its supporter. The analysis of the constitutional provisions of the Russian Federation, the decisions and orders of the Constitutional Court of the Russian Federation, the opinions of the leading Russian constitutionalists make it possible to define some separate subtypes of the public authority such as state authority and local government. It is stated that state authority is established by the constitutional provisions both as a the system of state bodies (state bodies of the Russian Federation and other federal state bodies, state governments of the Russian Federation and other state governments of the Russian Federation) and as a complex of powers realized by the corresponding bodies. Modern Russian statehood, which is characterized by active building of the local government in the governmental system, forms the demands to the mandatory structure of the local government bodies (representative body, head of the municipality, local administration) and shows the increase in some separate state powers which are realized by the local government bodies and on the basis of the granting of the public services. The author presents the variant of the common features of the federal, regional and municipal space levels which basically, characterizes public authority as a generic term. It is concluded that the establishment of such category as public authority by the Constitution of the Russian Federation makes it possible to form a modern model of the interaction between state authority and local government, provide constitutional guarantees in the provision of the state and municipal services in order to realize individual constitutional rights.