日本的lesson study是教師專業發展的實踐活動，教師們協同合作發展學課計畫、教學和觀察學課，並蒐集學生學習的相關資料，最後使用觀察結果修正學課計畫；在研究過程中，教師們能夠學得許多有效的教學實踐，其結果可以引發教師的專業發展和改善學生的學習成效。 Lesson study是日本小學教師為改進課堂的教學而進行的課程與教學的研究，其定義是「學生學習課題的研究」或是「一課的研究」，並蘊含著「研究課程或檢驗教學改善策略的意圖」。Lesson study是一種教師專業發展的型式，教師們協同合作計畫、教學觀察與反省學課，並蒐集學生的學習資料與檢驗實際的學課，以修正研究的學課計畫。此研究提供一個「教學視窗（window）」，透過此視窗讓老師們共同參與教學歷程；其程序包括設定目標、計畫學課、實際教學、修正與再教學、反省與分享結果等。 根據文獻探討的結果，Lesson study能夠引發教師專業發展的資源體系，可以從學校系統支持、教師的自我發展動機以及教師自我的核心要素等三方面來說明。

In Japan, lesson study is a professional development practical in which teachers collaborate to develop a lesson plan, teach and observe the lesson to collect data on student learning. It is a process that teachers engage in to learn more about effective practices that result in promoted teacher’s development and improved learning outcomes for student. Lesson study is a curriculum and teaching research for the teachers of elementary school in Japan to improve their teaching skills in class. Its definition is a research of learning lesson or a study of lesson which implies curriculum research or examination of teaching strategy. Les- son study is a pattern of professional development, including teacher’s collaboration to develop a lesson plan, teaching and observing the lesson to collect data on students’ learning, and using their observations to refine their lessons. It provides a vision window of teaching, and through it a teacher can share his or her teaching experience together with group teachers. The process includes setting goals, planning the lesson, teaching practice, revising and re-teaching, reflecting and sharing results and so on. According to the results of inquiry, lesson study promotes teacher’s professional development resources, including school system's support, teacher's self-development motive, teacher's self-core elements and so on.