The Russian Federation is a multinational state, in which the main ethnic groups of the Altai language family are represented. Solving the problems of the Mongol-Manchu-Korean interaction in the antiquity on the materials of various sciences is fraught with great difficulties, since these peoples were in constant linguistic and cultural influence on each other. In order to illuminate the complex ethnic history of peoples at the modern scientific level, it is necessary to better understand the connection of the ancestors of the Mongols with the history and culture of East Asia. The fundamental sources are the Chinese dynasty chronicles. The Korean and Buryat people are connected by the ancient Donghu tribe. It is necessary to consider Chinese sources about the Donghu tribe. The name Donghu appears in China in the Chunqiu era (722-481 BC). Dunhu from the Chinese language literally means eastern barbarians (dun - eastern and hu - barbarian ). They lived north of the kingdom of Yan. Russian researchers noted the proximity of the inventory of monuments culture of the upper layer of Xiajian to the materials of the palace culture of East Transbaikalia. The Korean and Buryat people are also united by the ancient Huns. If the Mongol-lingualism of Donghu, Syanbi and Shivei, Juanjans and Khitan is not currently in doubt among researchers, then the ethnicity of the Huns is still in the field of discussion and needs to be resolved. They were considered as pure Tungus or as a people of mixed Mongol-Tungus origin. Obviously, to understand the history of the early Mongol ethnic groups, one should clarify the positions on the genesis of their eastern neighbors - the Tungus-Manchu peoples. The study showed that in the genesis of the Tungus-Manchu peoples of antiquity, southern hypotheses related to the settled population of southern Manchuria should be preferred. Korean people come from the Altai region. During the Neolithic period, the creation of the people of Korea took place within the framework of the northern Mongolian race. At the same time, Evenki, as well as Koreans, are characterized by large absolute face sizes, but this feature distinguishes many Mongoloid groups and is not specific to Evenk. The Donghu peoples and the Joseon state have much in common. An analysis of the available materials suggests that the Donghu tribes in the late Bronze and Early Iron Ages lived in southern Manchuria and the surrounding regions of Inner Mongolia. This is evidenced by the single root of the Mongolian, Tungus-Manchu and Korean languages within the Altai language community. The state of Pue (Fuyuy) on the Sungari River was both Korean and the state of the Tungus-Manchu. For example, a number of scientists attribute the invention of stirrups to the ancestors of Koreans. From all this we can draw the following conclusions: - The ancient stage in the history of the Mongolian peoples is associated with the peoples of the Donghu group of Chinese written sources. Archaeologically, the Donghu are represented by cultural monuments of the upper layer of Xiajian in southern Manchuria. - An analysis of modern points of view on the formation of the Hunnu culture allows us to support the Mongolian concept of the ethnic origin of this people. The Hunnish advance into the Central Asian steppes involved them in active contacts with the peoples of the Iranian and Turkic languages. - The questions of the genesis of the Tungus-Manchu peoples are still far from being resolved. - It was established that in the works of linguists an assumption was made about an ancient unified ethnic community consisting of the ancestors of the Tungus-Manchu and Mongols.