The article analyzes lexical-semantic processes in modern scientific texts. In the aspect of the literary norm, the activation of rarely used, reactivation of outdated, determinologizing, expansion of the meaning of special, functioning of foreign vocabulary was observed. The word-forming tendencies of the scientific style are highlighted, taking into account the internal laws and potential possibilities of the Ukrainian language. Scientific style, under the influence of the trends of language democratization, expands its own possibilities in the choice of linguistic means, activates the passive fund of the literary dictionary, creates new contextual opportunities for the development of semantic connotations. The main challenges of this sphere of linguistic life are the spread of general negative tendencies of the lexical norm (restriction of word-formation potential, excessive variability, tracing of determinologized nominations and terms) and, as a result, the threat of losing the basic definition of style as a standard of literary language. In the aspect of stylistic norms, excessive expression of texts due to the use of means not typical for scientific language was recorded: colloquialisms, neologisms, ideologues, slangisms, etc. Such processes cause the phenomenon of stylistic polymorphism with the possibility of destroying the established functional capabilities of the language. Keywords: scientific style, scientific text, literary norm, stylistic norm, lexical-semantic processesces, linguistic expression.