Abstract: The purpose of the study is to find out the specifics of word formation in Chinese Russian-learners’ interlanguage. In the process of mastering a second language, interlanguage is considered as a language system in which exist its own rules and function, which differ from the rules of both the native and the target languages. The article updates the concepts of the term "interlanguage" in recent studies in Russian linguistics, discusses the common characteristics of interlanguage, analyzes speech features and written language materials related to interlanguage of two groups of Chinese philology students studying Russian language at the Faculty of Philology in Peoples' Friendship University of Russia. The novelty of the research lies in the fact that the author for the first time systematically described the specifics of word formation in Chinese Russian-learners’ interlanguage in aspects of prefix, suffix, word endings, etc., explained the reasons for their existence. The obtained research results provide useful recommendations to teachers working in the field of foreign language teaching; the results can be especially useful in classes for teaching Chinese students Russian language. The material of this article can also be used in the process of compiling textbooks and teaching aids on applied linguistics and the discipline of Russian language.