State finances have been considered as the public phenomenon for over one thousand years. Almost as old as state finances are also theoretical representations about them. This is the point to which are devoted many scientific works from all topical problems of social science. From the practical point of view this question has been one of the most actual. In fact, eight hundred years ago main social collisions of public finance questions generated Parliament in England, as public institute and parliamentarism, and one of the greatest achievements of human civilization. But the convincing answer to the question about the valid legal nature of the public finance, the great part of which make the treasury revenues in nation-wide duties payments has not been found yet. There exist plenty of various theories and doctrines on this problem, a part of which are imposed on one another to a certain measure and another part - mainly mutually exclusive and opposite. In the given report we compare the western financial - legal doctrine about the nature of state finances and the newest views of them in some post-social countries, first of all, in Ukraine and thus try to understand this unique phenomenon of a human society deeply, and adequately.