Although students are the key actors in their transition to higher education, there is limited research concentrating on student agency in a successful transition. This study examines how Chinese students actively and effectively manage their transition to the Sino-foreign cooperative university (SFCU). In X University -- one of nine SFCUs in China, we conduct semi-structured interviews with 35 Chinese undergraduates and analyse the data through the grounded theory method. We argue that Student Initiative (SI) is a key capability in managing student transition. And we conceptualize SI as a five-dimensional construct comprised of self-consciousness and self-reflection under the cognitive aspect, self-driving and self-adapting under the behavioural aspect, and positive feelings under the affective aspect. Moreover, we identify the impact of SI on students' academic and sociocultural transitions. Suggestions are put forward for students and SFCUs to enhance SI and facilitate student transition.