To reconstruct the true history of Mongolic peoples it is of utmost importance to investigate the process of formation of their peripheral ethnic communities. The article examines the history of formation of the understudied Mongolic ethnos of New Barghuts (Mong. Shine Barga) residing in Northeast China (prefecture-level city of Hulunbuir, Inner Mongolia Autonomous Region). Before moving to Hulunbuir, the mentioned group had been a part of the Baikal tribe Khori. In the 13th century, the steppe Mongols referred to the population inhabiting the Baikal region as ‘Bargut’ which was due to the name of the territory ― Bargujin Tokum. In the 17th century, the given nickname was most often used to denote the Khori clans who were tributaries and subordinates to Tsetsen Khan. By orders of the Mongolian Khan, they would form ancillary military units within corresponding troops, which would keep them long in Eastern Khalkha. Those were the Manchu people who virtually invaded Mongolia and, following suit of the Mongols, started calling the Transbaikalia Khori ― ‘Barghuts’. Having conquered Southern Mongolia, they proceeded with the establishment of a banner system in Khalkha. In Tsetsen Khan Aimag, the Khori people were also included in a banner. Between 1655 and 1670, for contribution to the powerful state and army the Manchu court bestowed upon them an honorable name ‘New’, which became a component of the common name of the New Barghuts. In 1734, the Qing authorities resettled the Khori people to Hulunbuir making them frontier guards. There were to form some eight banners, i.e. one military-administrative unit. It was there where the loss of relations with the former motherland and ultimate separation from their fellow tribesmen of the Baikal Region caused by the 1727 establishment of China-Russia border resulted in the Khori people experienced dramatic transformations of their ethnic identity and name. The mentioned processes predetermined that the name ‘Barghut’ along with the word ‘New’ got an ethnic coloring and from then onward was perceived as an ethnonym, and they started recognizing themselves as a separate, independent ethnos of Shine Barga. In this context, the Khori genealogical myth about Khoridoi Mergen got significantly transformed within the social consciousness of the New Barghuts. The new ethnic identity lead to a radical restructuring of their ethnic composition. The final stage in the process of formation of the New Barghut community took place in the late 19th century.