The significance of the kinship relationship between the mother's brother and sister's son (avunculate) was one of the most discussed topics in the history of social anthropology. Two theories of pre-Schneiderian age – descent and alliance approaches – both consider avuncular relations as being tense and contradictive, associated with certain privileges of the maternal uncle and his senior hierarchical position in relation to Ego. This paper tries to establish the relevance of this classical anthropological theme to contemporary social and political realities in Buriad society, specifically to extend the discussion of the classificatory/metaphorical use of avuncular kinship terminology to a new context – that of diaspora relationships with homeland and host society. A recent tendency in kinship studies argues that kinship terminology can be employed flexibly to handle relationships of various kinds, and suggests that kinship terms should often be understood as referring to a kind of social relationship rather than to a specifically genealogical connection. Two cases, which I present in the paper, show how Buriad diaspora communities in Mongolia and Inner Mongolia (China) involve the avuncular relationship to define their concerns and tensions in relation both to colonisers in the homeland in Russia and to the social inequality of migrants in their host societies. This local phenomenon shows that kinship terminology continues to have a wider social significance, being used, for example, to express current inequalities of power and the impact of political changes on local experience.