The problems of development conception legal system in the contemporary common lay theory and international legal doctrine, maintenance of categories «international legal system» and «national legal system», precondition and general directions of their interaction are considered in this monograph. The analysis of theoretical conceptions and description of juridical mechanism action of international legal norms in law systems of contemporary states are discussed too.

In the opinion of author international law and national law are absolutely different legal orders. That is why former can not direct regulator of relations in the sphere of latter.

For conferring force to the international legal norms inside state they must transform in the norms of national law, in other words, acquire the force of norms internal state law.

The procedure of transformation is characterized for all cases and methods of putting in action of international legal norms inside state and realization of transformation needs an issuance respective national legal act.

The international legal norms occupy a solitary post in the normative massif of the Russian legislative system, functions equally with the Russian law, must interpret and use in the light purposes and principles of international law, and intergovernmental treaty.