Abstract: As a member of minority nationalities, after Tibetan undergraduates entered other cultures from their familiar mother culture, on the one hand, they faced dilemma of ethnic identity, on the other hand, they faced torture of acculturation, and at the same time, they also faced disturbance of mental alienation. Combining with qualitative and quantitative study, this study employed 285 Tibetan undergraduates to examine relationships among Tibetan undergraduates, ethnic identity, acculturation and mental alienation. The results showed that:1,Tibetan undergraduates, ethnic identity mainly involved in three aspects: negative ethnic identity, positive ethnic identity and mainstream culture identity. Different aspects of ethnic identity were affected by different factors. But generally speaking, Tibetan undergraduates, ethnic identity might be predicted by the number of Han nationality friends, by the time of learning Chinese, by parents’ nationality identity and the reception of Han nationality.2,There existed abroad positive correlation or negative correlation between ethnic identity and acculturation strategies.3, There existed remarkable positive correlation between negative ethnic identity and normlessness, social loneliness and culture separation；But there was no remarkable correlation between host culture identity and positive ethnic identity and normlessness, social isolation，culture separation and self-separation.

Key words: Tibetan undergraduates, ethnic identity, acculturation, mental alienation