Introduction. The research of Russian grammar textbook of I.A. Heym (Bernhard Andreas von Heym, 1759-1821) is of interest for the history of pedagogy, as it allows revealing the features of teaching Russian as a foreign language in Russia at the end of the 18th century. The study of the sources of three editions of this grammar allows us to understand which of the existing grammatical traditions had the strongest influence on the authors of the Russian language textbooks of that time. The purpose of this research is to study the features of the description of Russian grammar in three editions of the textbook by I. A. Heym, allowing to establish their sources and reflecting the methodological views of the author. Materials and Methods: the research material is the sections “Name”, “Pronoun” and “Verb” in three editions of the Russian language textbook for Germans “Russische Spraclehre für Deutsche” (1789, 1794, 1804). The description of not all grammatical categories of the name, pronoun and verb is subjected to analysis, but only those whose interpretation is different in various textbooks, and causes difficulties for foreign students: gender and declension of nouns, degrees of comparison of adjectives, categories of pronouns, tenses of the verb. Research methods: descriptive, comparative and analytical. Results: Three editions of Heym’s Russian grammar for Germans have an internal unity, but at the same time differ from each other in details. The first version of the textbook (1789) was based on the grammar of M.V. Lomonosov, and in some cases on the grammar of J. Rodde. The 1794 edition is also based on the grammar of M.V. Lomonosov, but at the same time on the grammars by J. Rodde and P.I. Sokolov. The text of the 1804 edition reveals a dependence on the academic grammar of 1802. I.A. Heym was more of a pedagogue than a linguist. His merit lies in the fact that he sought to make grammatical rules more accessible and understandable by systematizing and simplifying them and giving more common examples.