The aim of the article concerns the analysis of the lexico-semantic transformations of phraseological units in the English language media. The material of the study is 200 examples of lexico-semantic transformations, which are considered in the aspects of their semantics, functioning, expressive stylistics, cognitive basis and linguocultural specificity. Analyzed lexico-semantic transformations are based on the thematic unity, synonymy, paronymy, antonymy. The listed types of transformations concern the key principles of human cognition: the relations of identity, analogy, opposition, group affiliation. The basis of the study is a comprehensive approach to the linguistic phenomena research in the aspects of traditional lexicographic, structural-semantic, cognitive and stylistic analysis. The integration of scientific paradigms allows to identify cognitive and linguistic basis for substitutions, explains the choice of the components according to the pragmatics, communicative situation, linguocultural peculiarities. The article emphasizes the fact of transformed phraseological units reference to speech, the existence of associative connections, on the basis of which it is possible to recognize the conventional and transformed versions. The author deals with the issues of phraseological units and free combinations different nature, reveals the wide systemic possibilities that allow paradigmatic relations syncretism, underlines the unique nature of the pragmatic influence, which allows to decrease addressee’s attitude. The originality of the study concerns the analysis of lexico-semantic transformations of the phraseological units determined by a set of linguistic and extralinguistic factors (cognitive principles, language features of the phraseological units, functioning, addressee intention and etc.).