The archival collection of Professor S.A. Vengerov was one of the most important sources for the development of a number of branches of humanitarian knowledge in the USSR, including Slavic studies. However, through almost the entire pre-war period the systematic use of the Vengerov archive in the interests of science was not possible, the problem of its preservation was the key-point. Not all the documents on the history of the Vengerov archive during the period after the death of his collector were brought into scientific circulation. In this publication, 18 documents from the Central State Archive of Literature and Art of St. Petersburg and Archive of the Russian Academy of Sciences are introduced. They demonstrate the modus vivendi of the largest archival collection on the history of Russian literature. As these documents show, the idea of creation of a separate research institute based on the Vengerov archive at Petrograd (Leningrad) University was rejected. During the period of relative institutional stabilization of scientific life in the pre-war USSR, it was decided to transfer the archival collection to the Institute of Russian Literature of the USSR Academy of Sciences (“Pushkin House”). A separate problem, which the Soviet science had to face, was preservation of the archive of S.A. Vengerov as a whole, undivided unit.