The purpose of this study is to investigate interpersonal isolation of Mainland exchange students in Taiwan. This study mainly adopted seven exchange students, who exchanged in a comprehensive university in central Taiwan in the Spring of 2019, four Taiwan students and two professors in this university as research subjects. Through in-depth interviews, participant observation, document analysis and thirty-seven samples for questionnaire, various data were collected in two months so as to explore their social isolation. The results show that during the exchange period, most of the Mainland students do face the social isolation issue, which is embodied in the following aspects: 1. low interaction except academic communication, 2. shallow friendship, 3. mutual exclusion and separation from Taiwan students, and 4. tendency toward co-nations Chinese students to get easier interpersonal acceptance. Finally, this study provides several suggestions, in terms of taking the initiative to establish interactive strategies with domestic students, participating extra-curricula activity of social club, implementing cultural orientation prior to their arrival, and blending arrangement for cross-strait students in their dormitories.