The practicum in teacher education is considered as the application of the theory into practice. (Zeichner, 2009). However, the disconnection between the academic learning and practicum (Alen & Wright, 2014; Kwenda et al.2017) has been a barrier for pre-service teachers' learning. My research introduces a new approach to bridge this gap by comparing an on-campus and an off-campus practicums. In the on-campus practicum, the lecturers in academic learning stage also mentor the pre-service teachers in the practicum. Sociocultural Theory (Vygotsky, 1978) and Activity Theory (Engeström 2015) are used as the tool for data analysis. The participants, included the university leaders, lecturers, mentors and pre-service teachers of two English language faculties in Vietnam were interviewed, the pre-service teachers were observed and formal documents were analysed. The findings indicated that the systematic change in the on-campus practicum facilitates the translation between theory and practice. In addition, the long-term relationship resulted in the devotion of the mentors to their mentees. In the meanwhile, the pre-service teachers in the off-campus practicum bounced between the two separated systems and suffered more tensions.