Purpose: This study aimed to examine the influence of four factors (intellectual, instrumental, self-actualizing and CPD cultural factors) on teachers' engagement in continuing professional development (CPD), specifically in the context of three lesson study activities: teaching research team activity, teaching research group activity and research lesson study activity in Chinese school settings. Design/methodology/approach: A mixed-methods design was employed to examine the perceived effects of these factors on the engagement levels of 33 primary school teachers who participated in lesson study activities. The research used a questionnaire survey and semi-structured interviews as data collection instruments. Findings: The results indicated that participants demonstrated higher levels of engagement in research lesson study and teaching research group, whereas their engagement in teaching research team was comparatively lower. Intellectual and CPD cultural factors emerged as the strongest predictors of engagement in all the activities. Self-actualizing factors highly influenced teachers' engagement in research lesson study. Instrumental factors mainly affected novice teachers and some mentors in the teaching research group, but not others. Originality/value: This study addresses a gap in the existing literature by investigating factors influencing teachers' engagement in lesson study professional development. The observed variation in teachers' engagement behaviors and attitudes provides policy makers and school leaders with a deeper understanding of the underlying mechanisms and effects of these engagement factors on teachers' professional development.