The paper addresses quantitative analysis of the Ukrainian vocabulary. The object of the research are lexicographic sources: bilingual Ukrainian-Russian and monolingual dictionaries of the Ukrainian (phraseological, synonymic). The main method of research is parametric analysis, developed by V. T. Titov. The point of the method is selection of four sets of words step-by-step, which reflect four important systemic characteristics of vocabulary (usage, co-occurrence-range, number of meanings and richness of synonymous connections). The study puts them as functional, syntagmatic, epigmatic and paradigmatic parameters. The functional core of the Ukrainian vocabulary is made up of lexemes with a length of 2 to 5 sounds. The syntagmatic core of the Ukrainian vocabulary is represented by 1395 words with from 2 to 122 phraseological units. The epidigmatic core of the Ukrainian vocabulary is made up of lexemes with the number of meanings from 3 to 10. The paradigmatic core includes synonymic row with from 7 to 66 members. These varieties combined allow to identify the lexico-semantic core of the Ukrainian (the words included in three and four private cores). The research made it possible to find the dominant of the lexico-semantic system of the Ukrainian. This is the verb “іти”. Since the lexical composition of the language is represented as a system of interacting lexico-semantic fields the paper was about to identify the fields that are most important for the lexical system of the Ukrainian. The results obtained may be used in typological and comparative studies.