The description of the popular dialects is a continuing concern of our Institute since 1946. 6 years ago, it was founded the academic department – The Sector of Dialectology. In this article, the author evokes the main objectives and results achieved through researches of Romanian subdialects from the east of Prut, such as: the dialectological surveys in the giant space from Tisa to Amur, the elaboration of the Regional Linguistic Atlas in 8 volumes, the participation to the drawing up of three pan-European linguistic atlases: Atlas Linguarum Europae, Atlas Linguistique Roman, Общекарпатский диалектологический атлас. We participated in the projects „Romanian subdialects from lateral and isolated areas” and „Romanian subdialects from the east of the Carpathians. Ethno- and sociotexts„ (in collaboration with the dialectologists from Bucharest and Iasi respectively). Currently the subject of investigation concerns the onomasiological aspect of the motivation in the dialectological study.