This research investigated the relationship between cross-cultural adaptation, acculturation strategies, social support, and the characteristics of students among the mainland students in one university in Hong Kong. Using self-administered questionnaire survey design, 218 mainland students in the university were surveyed. The results suggest that (1) social support was significantly correlated to cross-cultural adaptation; (2) the effects of family support to cross-cultural adaptation was stronger than the friend support and university support; (3) social support, in general, was not related to any acculturation strategies. However, friend support was negatively related to the strategy of separation and positively related to the strategy of integration; (4) cross-cultural adaptation was negatively related to the strategy of marginalization and separation, but positively related to the strategy of integration; and (5) except the source of tuition, none of the characteristics of the mainland students lead different levels of cross-cultural adaptation.