Functional equivalence of foreign innovations is referred to as the ability/ inability to be replaced by other linguistic units (vernacular, borrowed, equivalent or close in meaning of usage) without changing the meaning of the utterance. This approach reveals intralingual causes for the fixation of foreign language units in the lexical-semantic sphere of the recipient language. It enables to solve the problem of foreign neologisms being appropriate or redundant. Foreign innovations, or xenolexis, are words from a foreign language, both assimilated and non-assimilated, which penetrated into the Russian language from the 1980s until the present time. Basic groups of lexicographic sources, essential to the study of the functional equivalence of foreign innovations in the Russian language in the beginning of the 21st century are the following: 1) dictionaries of any type stating the condition of lexical-semantic system in the mid 1980s; 2) reference-books of new foreign words and new vocabulary; 3) foreign language words published at the edge of the centuries and in the 21st century, including explanatory, bilingual and grammar dictionaries; 4) jargon dictionaries (youth slang, student slang, computer, business, city jargon, etc.); 5) electronic dictionaries of various types. Relationships typology of the analysed language units jointly with their equivalents in the language and speech takes into account syntagmatic and paradigmatic approaches to the analysis, as well as particular features of nomination: 1) non-equivalent nominations - primary nominations (which do not have one-word analogues in the recipient language having identical denotative semantics); 2) equivalent nominations:.) absolute synonyms (doublets) - secondary nominations (naming the already denoted realities); b) ideographical (notion) synonyms - primary nominations; c) functional and stylistic (interstylisti.) synonyms - secondary nominations; d) affective- expressive (connotative) synonyms - secondary nominations; e) synonyms differing from the viewpoint of active and passive vocabulary - secondary nominations; f) combined synonyms: semanticstylistic and affective functional semantic - primary nominations, affective stylistic - secondary nominations.