The objective of the article is to propose a method of studying the special lexis, i.e. EST vocabulary on the basis of frequencies distributions of words in the text. The analysis of frequencies distributions of words provides information about what vocabulary to focus on and additional techniques for studying it. The estimates of word frequency distributions will help specialists in education and learners develop a feeling, which words should be paid attention to and which are infrequent. Having determined the frequency counts of vocabulary, a researcher or a student will get information about which words compose EST vocabulary and additional techniques will be possible for studying special vocabulary. On the basis of a special computer program, it has been examined the frequency distribution of word-forms in the typical article and the practical applications of frequency list such as lemmatization of word-forms, the study of collocations, restoration of sentences, and the initial text. An observation of frequency lists helps a lot in the selection of texts for English teaching. The selection made on the basis of frequency lists allowed determining the lexical field of words, i.e. which would be taught.