The article aims to demonstrate the results of research and bringing to the technological implementation, in the Library for Natural Scien­ces of the Russian Academy of Sciences (LNS RAS), of a full cycle of works, from identification of rare books in the collections, their description and scanning, to their registration in the Union Catalog and Electronic Library. The author gives a brief description of the software package developed at LNS RAS for creating the Electronic Catalog and full-text Electronic Library of Rare Publications, as well as the scheme of automated interaction of all technological departments involved in the process. The information on practical implementation and directions of the technology development is given. The article presents a brief review of the research, with the identified part of the collection of rare publications of the LNS RAS. For the first time, the Central Library of the LNS RAS implements the Union Catalog and Electronic Library of Rare Publications, reflecting not only the bibliographic information on the publications, but also the data on their specific features (author’s inscriptions, bookplates, stamps, etc.). Rare publications previously inaccessible to researchers, though already used by scientists of the RAS institutes, are introduced into scientific circulation. The article identifies and describes materials about geographical expeditions of the 18th—19th centuries and samples of Russian and foreign book printing of the 18th century. For the first time, the LNS RAS conducts research related to the history of Russian science and printing, and identifies bookplates and proprietary marks of Russian scientists, which have not previously been reflected in ca­talogs. This opens a new cultural layer of historical data, now available to researchers.