This research explores how and what strategy is applied for preparing sustainable English teachers' professional development. This study utilizes lesson study strategy-based clinical supervision and quality assurance. Lesson study is a kind of action research based on a cycle base. This study is also recognized as research and development. Based on conceptual and empirical study, it is found that three grand principles of adding quality lesson study implication. Those are cycle reflection in accelerating the teachers' competencies in English language teaching, clinical supervision nuance, a quality assurance principle by implementing the plan, do, check, and act strategy. This research successfully finds a model for preparing a prospective and sustainable professional teachers development based on lesson study, blended with the clinical supervision and a quality assurance implementation. The outputs consist of connection among professional English teachers; accelerating realization learning and teaching quality based on reflection implication; forming the open attitude and reflecting discussion and depth analysis; building a self-responsibility and awareness as professional teacher attitude; helping one each other in the professional teacher community for accelerating teaching quality by utilizing clinical supervision. Finally, the outcome is obtaining candidates of English professional teachers, prospectively and sustainably, with high-quality EFL teaching performance in national competitiveness.