Background. One of the indicative characteristics of human language, especially which has a significant number of speakers, is the ability to changes. According to historical and cultural context, a language can undergo changes at different levels. Mostly both the emergence of new words and the disappearance of those that already exist in the language, are associated with technological progress, intercultural contacts, socio-political processes, etc., and all these processes are quite dynamic. Since events in these areas of life are relatively fast, the vocabulary must change at the appropriate pace to meet the needs of speakers. Therefore, in accordance with the above, we can say that the language contains both active and passive vocabulary. Active vocabulary includes common vocabulary, as well as some special vocabulary (mostly general scientific terms), which is also actively used. Accordingly, the passive stock consists of words that speakers use almost or not at all in everyday communication, using them only in certain areas of activity. These can be stylistically colored words (such as poetics), obsolete (archaisms and historicisms) or new ones (neologisms) and limited in use by a certain social stratum (jargon, professionalisms) or territory (exoticisms, dialectisms).
 The purpose of our investigation is the analysis of lexico-semantic features of historicisms and archaisms in the novel «Brothers…» by Vasyl Shevchuk.
 Methods. The choice of research methods depends on the purpose of the article, its objectives and the object of study. In our scientific work general scientific methods of analysis, synthesis, comparison are used; linguistic methods, in particular, such as descriptive one – to interpret the meaning of obsolete units; the method of integrative analysis, which is the basis of a comprehensive study of a set of various aspects that we touch on when studying outdated vocabulary in the literary text, as well as contextual-interpretive method – to describe possible strategies for perceiving the literary text.
 Results. Archaisms and historicisms are those units that were already obsolete at the time of publication of the novel (because the exact date of its writing is unknown). This will make it possible to single out those obsolete words that the author used intentionally, for a specific purpose, and which in terms of synchronicity were already obsolete during his lifetime. It is the stylistically conditioned use of archaic units of vocabulary that we need for further analysis of their role in the language of the work and its poetics in general. Guided by this principle, we can determine that the author used 300 units of outdated vocabulary within the novel (excluding word forms of one word and repetitions). Regarding the differentiation of this vocabulary into archaisms and historicisms, we can say that their relationship is as follows: of the 301 obsolete lexical units, 87 words are archaisms, and 214 are historicisms.
 Discussion. According to the denotation criterion, we determined that the novel is predominated by historicisms (which in its semantics can be divided into supergroups «State and Society», «Military Action and the Army», «Life, consumer goods», which contain relevant groups of vocabulary) . Somewhat less common are archaisms, which can be divided primarily on a formal basis, i.e. on what level archaism belongs to outdated linguistic units (phonetic, morphological, word-forming, semantic or lexical); lexical archaisms can be divided into some thematic groups (such as architectural terms, names of diseases, body parts, etc.). The prospects of the investigation relate to the study of its translation into English.