The present study was conducted with the aim of pathology of the process of implementing the lesson study (lS) in primary schools and providing a framework for overcoming its challenges.This research was conducted in a qualitative manner with an approach based on data theory. Potential participants included principals and teachers of schools in West Azerbaijan province. Using purposive sampling method and theoretical saturation technique, 12 school principals and 18 teachers who had a history of participating in the project were selected. Data were collected using a semi-structured interview protocol. Calculation of reliability and validity of the data was done using two methods of reviewing the participants and reviewing non-participating experts in the research. Data were analyzed inductively, by theoretical coding method. Findings obtained from interviews of principals and teachers were classified in 5 themes: 1) Sharing knowledge and experience of teachers 2) Culture of team and group learning 3) Culture of thinking and research 4) Development of professional knowledge of teachers 5) Improving teaching methods and improving student learning. Five central categories were extracted from the challenges and problems experienced by principals and teachers. 1) Psychological and environmental space governing individuals 2) Artificiality of teaching 3) External to internal motivation 4) Unequal participation of members in the project implementation process 5) Insufficient knowledge and skills about the project. Also, at the end, the conceptual framework of interaction, challenges and strategies for more effective implementation of Lesson study in primary schools were presented.