This article explores the impact of educational mobilities on the ethnic identity construction of minority students in China. Adopting 'temporality' as an analytical tool, the article highlights the dynamic temporal multiplicity in ethnic identity construction by comparing longitudinal in-depth interviews of a Mongolian student and a Tibetan student. This multiplicity of temporality is manifested in three aspects: temporality of ethnic othering; temporality of ethnic identity awakening; and temporality of 'worldly time' and 'ethnic time'. Both 'worldly time' and 'ethnic time' entail distinctive understandings about these students' pace and priorities in life. Both students defer their 'permanent' ethnic identity to an imagined future. Yet, adopting the gaze of the dominant others, both students subconsciously constructed an essentialist view of their ethnic cultures as fixed and stable, and those of the dominant cultures as alive and fluid. This article enriches our understanding of the politics of subjectivation through the lens of 'temporality'.