In the article is studied of concept ≪state sovereignty≫, his international legal properties and features of conception of state sovereignty in an international law on the modern stage. The special value undertaken a study acquires in connection with a loss Ukraine of sovereignty above separate parts of territory of Ukraine. Given the international legal acts, which contain legal opinion of the events of 2014 in Crimea. The legal envisaged concept of state sovereignty is absent in an international law formally. The analysis of doctrine approaches of lawyers-specialists in international law is conducted to the concept ≪state sovereignty≫. The analysis of legal literature witnessed, that a concept ≪state sovereignty≫ in an international law is characterized by next signs: political and legal independence, value as primary international legal subject; needed for exceptional supremacy of state power and envisages insubordination of power of other state; conditioned by legal equality of the independent states and is in basis of modern international law. State sovereignty is characterized international legaland internal aspects. Under the external aspect of sovereignty is understood independent of other subjects of international law. The internal aspect of territorial supremacy means the right of the state exercise its authority within its territory Sovereign equality is a concept, what derivant from a concept ≪sovereignty≫. But in most international legal acts, the concept of ≪state sovereignty≫ is used primarily in combination with the principle of territorial integrity of states. Principle of territorial integrity essentially comes forward as a major backer-up of state sovereignty, as exactly territory is an obligatory sign of any state, sphere of action of his sovereignty. The concept of state sovereignty in international law is based on the principles of international law, primarily the non-use of force and threat of force in international relations, the sovereign equality of states, non-interference in the internal affairs of states, inviolability of borders and territorial integrity of states. At the national level, appropriate to speak of sovereignty as a property of the state, and at the international level, the principle of respect for state sovereignty. Thus, state sovereignty remains the base of the international legal system. The most serious crime against state sovereignty in an international criminal law is a crime of aggression. In the framework of international law, it is expedient to develop more effective mechanisms for the protection of state sovereignty, taking into account the need to protect it from contemporary forms of manifestation of an international crime ≪aggression≫, which is accompanied by information, trade, as well as ≪hybrid≫ wars.