Abstract: The study aims to analyze and describe a development model of lesson study-based social science teachers, lesson study validation as a development model of social science teachers and a development model of lesson study implementation as a development model of social science teachers. It used a qualitative phenomenological approach and it was located at Muhammadiyah Schools of Sukoharjo regency, Central Java, Indonesia. The study was included in the action class research. The subjects of the study were the students, teachers, principals, head of educational agency, members of the regional house of representatives. The techniques of the data gathering employed the observation, documentation and in-depth interview. The technique of the data analysis applied the first order understanding dan second order understanding. It could be concluded that a development model of social science teachers used a modified lesson study approach, a lesson study validation employed two validations: closed and open classes and a development model of lesson study implementation applied four approaches) a four-stage and three-circle, scientific, active, cooperative, collaborative and comfortable learning and) teachers’ competency.