Through conducting an ethnography study to explore the influence of Japanese culture on the implementation of Lesson Study, this paper aims to explore the culture factors for developing Lesson Study. Despite many studies indicate that Japanese Lesson Study can effectively facilitate teacher collaboration, develop professional learning communities and enhance student learning performance, it cannot be deeply rooted in other countries. This study adopts Nonaka and Takeuchi’s SECI (socialization-externalization-combination– internalization) knowledge creation model as the theoretical framework to analyze the mechanism of Lesson Study, and conducted ethnographic studies in Nagoya and Aichi Prefecture to explore the influence of Japanese culture on the implementation of Lesson Study. Results of this study show that a high-trust culture in the Japanese society, a strong professional accountability of teacher, and a unique culture of Kaizen Kata for pursuing improvement are the critical elements for cultivating Japanese Lesson Study. School systems in other countries may cultivate these elements through developing an organizational learning culture to institutionalize Lesson Study. Keywords: Lesson Study, SECI model, Knowledge creation, Organizational learning culture