The approach to legal terms of art (or technical legal terms) form rhetorical perspectives is based on their place in legal discourse depending on the genre of the text. The division of legal texts by genres, proposed in the article, is grounded in Russian theory of slovesnost’, which was in the core of education in Russia in the second half of the 19th and beginning of the 20th centuries and was later developed in the works by Soviet professor of linguistics Yuri Rozhdestvensky and his students of rhetoric, philology and cultural studies. Law as a discipline in which ordinary words and terms of art behave in a different way than in other sciences poses many questions before the researchers, and these questions can only be resolved by using interdisciplinary approach, where rhetoric and theory of slovesnost’ provide one of the possibilities. The main legal genre of written prose is a normative act, that is why special attention is paid to the use of the terms in statutes. Different behavior of terms of art in texts of different genres is noted. Analysis of polysemy and homonymy in statutory texts and investigation of legal terms versus terms in other sciences is made. Special attention is paid to technical legal terms, which have different definitions in different branches of law, to legal definitions, which have different meaning in law and other sciences, to terms of “general science” (such as ‘assimilation’, ‘operation’, ‘balance’, etc.) and to those words, which can be used in legal texts in their ordinary or terminological meaning (e.g. ‘agent’, ‘defender’). A distinction will be drawn between the technical legal terms in legal theory and technical legal terms, which found their definitions in statutory texts or regulations.