The article is dedicated to the Honored Scientist of the Russian Federation, Honored Lawyer of the Russian Federation, retired judge of the Constitutional Court of the Russian Federation, Doctor of Law, Professor Oleg I. Tiunov (1937—2017) in connection with the 100th anniversary of the Institute of Legislation and Comparative Law under the Government of the Russian Federation. O. I. Tiunov is one of the outstanding domestic international law scholars. He developed a scientific concept for the application of generally recognized principles and norms of international law in the Russian legal system, and also explored other fundamental issues of the theory of international law, the law of international treaties, and the implementation of international law norms in the national legal system, etc.