Essential aspects of formation of terminological thesaurus in the field of aluminium industry are considered in the article. It is known that such dictionaries are usually ranked depending on the sphere of their activity. They may include technical dictionaries, phraseological dictionaries, dictionaries of synonyms, polytechnic dictionaries, special dictionaries in different directions, etc. This process of thesaurus formation not only ensures the integrity of the system, but also provides access to its content.