The main objective of this research is to provide a systematic phraseographic description of phraseological units used in scientific discourse. The study examines how such units are identified, classified, defined, and represented in phraseographic sources, with particular attention to their semantic structure, functional specificity, and contextual usage in scientific texts. Existing linguistic studies on phraseology and phraseography are reviewed in order to demonstrate different scholarly approaches to the description of phraseological units within scientific discourse. The relevance of this research lies in the fact that phraseological units, despite their stable structure, exhibit specific functional and semantic features in scientific texts that require accurate lexicographic and phraseographic treatment. The research tasks include clarifying the criteria for selecting phraseological units in scientific discourse, determining their typological characteristics, and analyzing methods of their phraseographic representation. To achieve these aims, the study employs a range of linguistic and interdisciplinary methods, including descriptive analysis, componential and semantic analysis, contextual analysis, and elements of communicative and functional linguistics.