This paper examines Tibetan ethnicity by studying the language ideologies among Tibetan students and their persistent roles in shaping ethnic boundaries at a Minzu University (MU). MU attracts the highest achieving ethnic minority students throughout China and explicitly aims to turn them into patriotic minority cadres. Hosting extremely heterogeneous Tibetans from different dialect groups, MU is an ideal field for studying inter-ethnic relations and in-group interactions among Tibetans. Ethnographic data reveals that Tibetan language has been a significant ethnic boundary marker and a crucial toolkit for ethnic empowerment. On one hand, it has been used as an exclusive way of distinguishing between 'pure' and 'non-pure', 'authentic' and 'fake' Tibetans, the latter of which are discriminated against on campus by both Tibetan and Han students. On the other hand, Tibetan language has been conveniently appropriated by the so-called authentic Tibetans to organise many ethnic cultural practices, resist the marginalisation of the Tibetan group, and achieve a higher ethnic status. Yet, Tibetans' discourses on 'authenticity' are rooted in the same principles of alterity and hierarchy under which minorities are subject to by the majority, that they unavoidably marginalise and stigmatise certain 'non-standard' yet culturally Tibetan populations.