The language of Sergei Yesenin’s prose is still poorly studied. The article aims to analyze Yesenin’s individual authorial formations extracted by the method of continuous sampling from the story Yar, the short story “Bobyl and Druzhok” and the novella At White Water. The main methods of analysis were descriptive, component, and contextual ones. As a result of the study, we identified Yesenin’s individual authorial lexemes, bilexemes and phraseological units. We recorded occasional names of everyday objects, natural phenomena, as well as names of people, animals and body parts formed by suffixation, prefixation and suffixation, and composition. For the derivation of adjectives the writer uses suffixation (with various suffixes, sometimes unproductive), occasional patterns (with missing stages in the derivation chain), and composition. To coin verbs, Yesenin chooses mainly prefixation-suffixation and prefixation-suffixation-postfixation methods. He also adds a derivational morpheme to an onomatopoetic word, which is occasional by nature. When coining participles and adverbs, Yesenin uses mainly traditional schemes, but takes the stems of occasional and dialect verbs as generating ones. His adverbs are mostly lexical occasionalisms and are formed mainly by prefixation-suffixation. We also recorded authorial particles and interjections in Yesenin’s prose. A features of the writer’s individual creative manner is the presence of the so-called bilexemes his works. Yesenin’s prose contains occasional phraseological units, in which a unit’s component is replaced, a unit is part of a comparative construction with a completely replaced predicative component, a unit is broken, a unit’s composition is expanded, several units are combined, a unit is shortened or dephraseologized. A separate group is units with the concept “God” – these are modified set phrases and formations created by Yesenin himself. The structural and semantic analysis of the transformed and authorial phraseological units showed their main functions: emotive, evaluative, transmitting additional information and saving speech resources. Transforming a phraseological unit, Yesenin introduces various semantic clarifications, enhances expression and achieves a comic effect. Occasionalisms are found both in the author’s speech and in characters’ remarks. The performed analysis of Yesenin’s individual authorial formations from literary prose, as well as the appeal to the poet’s lyrics give us grounds to conclude that, for Yesenin, occasional words and phrasess are not just a means of expression, but an integral element of his individual style that, on the one hand, emphasizes the originality of his language, and, on the other, brings it closer to the poetic traditions of folk speech, which indicates the versatility of Yesenin’s talent.