The authors investigate features of the way of life, culture and interethnic relations of the Kazakhs and the Tuvans living in Tsengel sum of Bayan-Ulegei aimag of Mongolia. The majority of Kazakhs live in their own state – Kazakhstan; the majority of Tuvans live in Russia, where they have a recognized position and territory – Tuva Republic. Kazakhs and Tuvans in Mongolia are the national minorities and do not have national-territorial status. However the Mongolian Kazakhs and Tuvans still keep their native language, ethnic consciousness and traditional lines of the culture. This article focuses on ethno-language and cultural situation of Kazakh and Tuvan communities, and interaction between them. In this paper, the authors introduced material that was gathered about the Kazakhs and Tuvans in Mongolia. Their studies are based on the results of their field-work in 2015 and 2017 and the research of Russian scholars. The academic value of this paper is that it displays features of historical and cultural communications of the Kazakhs and the Tuvans; illuminates the problem of the influences of host people on the economic way of life and culture of the Kazakhs and the Tuvans; identifies the main tendencies in the functioning of language, ethnic consciousness, ethno-linquistic and ethnocultural development of the Mongolian Kazakhs and Tuvans; discloses the nature of their interaction with the center in Mongolia; and reflects on specifics of the adaptation of Kazakhs and Tuvans to conditions of Mongolian statehood. Consideration of the above-mentioned topics was carried out in a number of specific directions, most of which had not been studied earlier.