This article mainly discussed the research of lesson study on science topics conducted in Hong Kong primary classrooms. The topics for study included “Water in Air”, “The Formation of Solar Eclipse” and “Flow of Electricity”. The article studied about the background and motivation of undergoing lesson study in Hong Kong primary schools, the process of conducting lesson study research and the research result. The results found that there were significant changes in students’ achievement in the pre-test and pro-test which reflected students’ effective learning in the process, there was also improvement in teacher’s teaching during the mode of “planning-teaching-evaluation” process. Lastly, the article also discusses the effect of the research of lesson study on teacher’s development, including personal, social and professional development.