Lesson study has attracted the attention of teachers and teacher educators over the past two decades, and practices vary from region to region and from school to school. This study, as a conceptual discussion paper, aims to discuss the modes of coordination of lesson study at the school level, based on comparative institutional analysis (CIA). CIA is a framework to investigate the 'rules of the game' that govern given organisations. The conditions of categorisation include three core foci: whether lesson study is essentially more subject oriented or student oriented, whether or not the entire school is involved and whether or not the members are consistent throughout the process. According to these conditions, five modes are generated, namely: subject expert mode (E-mode), subject departmental mode (D-mode), LSLC multiple layer mode (M-mode), LSLC initial concentration mode (C-mode) and LSLC initial participation mode (P-mode). These are based on the differing needs of teachers: E-mode and D-mode refer to the more subject oriented lesson study aimed at instructional improvement; M-mode refers to school reform based on the needs of students observed in the process of lessons; finally, C-mode and P-mode are introductory approaches to M-mode, requiring careful planning and management for scaling up.