The study explores Tolstoy’s linguistic innovations in his novella “Youth” and their role in the development of Russian literary language vocabulary and then identifies their narrative and artistic function. The relevance of this study stems from the need for a detailed examination of the relationship between Tolstoy’s linguistic innovations and his artistic system. The scientific novelty of the article lies in the fact that the authors conduct corpus and linguisticpoetic analysis of linguistic innovations in the novella “Youth”. The aim of the article is to identify and classify various types of author’s innovations and their role in the text. The research methods include a comprehensive sampling of occasional forms, their comparison with the usual norm using systemic lexicography data, a corpus-based method using contexts from Russian National Corpus to determine the future functioning of the lexemes in Russian texts, and contextual-semantic analysis to establish the narrative and artistic functions of these innovations. Using historical and modern explanatory dictionaries, the authors identify deviations of Tolstoy’s new expressions from the linguistic norm of the late 1850s. The National Corpus of the Russian Language traces the subsequent functioning of these lexemes in the language of fiction and shows the influence of Tolstoy’s word creation on Russians vocabulary. Furthermore, the ideological and artistic functions of each type of innovation in revealing the inner world of the characters and shaping the narrative are established. The authors proved that Tolstoy’s linguistic innovation is proved to be not a collection of spontaneous and isolated original word usages, but a purposeful poetic device for detailing artistic space. The research contributes to the theory of linguistic innovation and understanding the ways author’s style influences literary language. The prospects of the research include subsequent studies of the linguistic context of the biographical trilogy and applying the developed methodology to the analysis of the idiostyles of other 19th-century writers.