"Great Soviet Encyclopedia" (BO) is a huge encyclopedic publication that was published in the Soviet Union in 1926-1990. This encyclopedia contained information from various fields of knowledge: from history and politics to science and culture. In its pages, BO combined thousands of articles, maps and tables covering all aspects of human life. The "Great Soviet Encyclopedia" was considered not only a source of information, but also a symbol of the ideology of the Soviet era. The publication was developed with the aim of spreading "correct" information among the population, as well as stimulating patriotism and promoting Soviet policy. BO was a fairly authoritative source of knowledge and was used as a reference book not only in schools and universities, but also in various spheres of society. Due to its broad subject matter and high authority, the "Big Soviet Encyclopedia" occupies a special place in the history of Ukrainian and world encyclopedism, being one of the most important sources of knowledge in the past.