This article is devoted to the study of a number of Russian phraseological units and their relation to the history and cultural realities of a particular time, as well as the social and national environment in which they were formed. The author focuses on the actual Russian phraseologisms by their origin, which make up the core of Russian phraseological system and display distinct national and cultural identity. The author gives special attention to the idioms which have lost relation between the inner form and meaning. The author systematized and summarized information presented in lexicographical sources about their origin and functioning. The thematic classification of actual Russian phraseological units proposed by the author is based on the identification of their dominant features. As a separate group of idiomatic expressions, the author considers phraseological toponyms which brightly represent the relationship between language and reality. According to the author, the given group of phraseological units represents rich material for linguocultural analysis. The paper has both theoretical and practical significance. The results of the study can be used in teaching the Russian language as a second Slavic language.