The article reveals the mechanism of the right termination of proprietary relations in consequence of the adoption of the act of nationalization of property . The author makes attempt to solve the problem of civil protection of the right of ownership of the temporarily occupied territory of Ukraine from illegal encroachments on the part of the relevant local government area. The analysis of the civil legislation of the Russian Federation on the issues is investigated. It is proved that in matters of protection of the property rights it is advisable to use the legal means by the principle of «reverse procedural activity». Its meaning is to use the mechanism of protection of the rights provided for by the national legislation of the Russian Federation, along with the laws of Ukraine.