The article analyzes the history of the working out and adoption, as well as substantive provisions of the Agreement on the conservation of populations of European bats of 1991 from the positions of its interrelation with the Bonn Convention on the conservation of migrating species of wild animals of 1979. It reveals specific features and a special role of «frame» conventions in the regulation of international environmental relationships. The article considers the competence of the governing organs established under the Agreement of 1991. Basic directions of the national policy of states and international cooperation in the sphere of ensuring the conservation status of bats are considered on the basis of the most recent reports and statements of the Parties to the Agreement.