To ensure their teaching quality, it is important for student teachers to undertake self reflection on their teaching performance after supervised teaching sessions. With the goal of sharpening the teaching competence of student teachers, a dual function system that uses web based and video based technologies is being developed to facilitate self reflection by student teachers and the teaching supervisory role of teaching supervisors. This article reports on the development of a web enabled video system for encouraging student teachers to reflect on their teaching performance, using a guiding framework. The system enables student teachers to self monitor a video recording process during lessons in teaching practice, and make post-lesson self reflection without the constraints of time and location. Two key features are provided by the system to support student teachers and enhance the quality of reflection. One key feature is a guiding support for self reflection on teaching performance, using a four-dimension framework comprising curriculum planning and evaluation, pupils and pupil-teacher interaction, discipline and classroom management, and professional knowledge of teaching. A second key feature of the system is a 'video bookmark' function for the operationalisation of the reflective process. Copyright © 2009 ASCILITE.