Add to ORKGThe results of research of phoneme /a/ on the base specifics in Tatar language and characteristics of distribution of variants in Tatar lingual space are covered in the article. Some facts of the history of Tatar language forming and lingual contacts with representatives of other cultures may explain existence of several forms of phoneme /a/. Territorial isolation of some areals led to preserving more archaic phenomena. There had been also the influence of other languages. Variability of phoneme /a/ usage in central areal is the result of substrate, ethnic variety effect. Studying the nature of phoneme /a/ variants, specifics of distribution of their isoglottic lines in Tatar lingual space has great importance to solve some problems of the ...