In this study it was intended to explore how to implement metcognition mechanism into preservice teachers training. The subjects are four classes of students who took "instructional principles and strategies" in the fall semester of 2002. They were required to compose weekly reflection journal. In such a weekly journal, there are three sections, in terms of summary of content, personal insight and impact, and future implementation plan. In addition to composing personal journal, each participant was required to review at least two journals each week so as to broaden their perspectives. After the semester ended, a questionnaire was conducted. It was found that the majority of participants, now student teachers in many schools, highly appreciated the implementation and effectiveness of reflection journal approach. Finally, several randomized interviews were conducted to explore their feedbacks in depth. In the interview, there were several findings. Firstly, the implementation of reflection journal produced a long-term impact in their learning process. Secondly, in the process of composing reflection journal some were serious, while others were perfunctory. Thirdly, their motivation were highly inspired and maintained throughout the whole semester. Fourthly, the practice of reflection journal help generalization and implementation of what they learned into their current instructional practice. Lastly, the design of peer review helped participants to develop a positive interpersonal relationship among them, and provided various perspectives as their valuable reference.