The proposed textbook on the Belarusian language is the first in the history of Ukrainian-Belarusian ethnolingual and cultural ties. The textbook consists of an introduction and two main parts. The first part sets out the features of Belarusian literary phonetics, orthoepia, accentology, vocabulary, phraseology, spelling, grammar, in the second - a concise anthology - Belarusian texts are submitted. Belarusian phonetic and grammatical features are compared with the corresponding Ukrainian ones, Ukrainian parallels to Belarusian grammatical terms are given. The introduction and the section "Phonetics" are written in Ukrainian, in the section "Vocabulary and phraseology" a gradual transition to the Belarusian language is made and further presentation is carried out in Belarusian.