A description of a new 20-million-word file of Russian scientific and technical text, prepared on magnetic tape in a homogeneous machine format easy to use for many kinds of research on the Russian language. The file was compiled from texts obtained from Georgetown University, IBM Research, and the Foreign Technology Division of AFSC. The usable data, which were originally recorded on magnetic tape or punched paper tape in several formats, were encoded according to the text-and-catalog system developed at RAND several years ago in collaboration with the universities of Grenoble (France) and California (Berkeley). The present file contains more than a half-million words in each of the following fields: aeronautics and astronautics, aviation, biology, chemistry, earth sciences, electronics, mathematics, mechanical engineering, internal medicine, metallurgy, and physics; and smaller numbers of words in other fields of science and technology. 10 pp.