The purpose of the study is to analyze the lesson on history in the elementary school, 'National Unification under the leadership of Nobunaga,' and to evaluate the lesson by researching cognitive structure and conceptual framework of students, assessing their attainment levels and conceptual change and suggesting alternative lesson plan. In this study we used two devices, structure of knowledge and conceptual framework, researched cognitive structure in the lesson and alternative conceptual framework of each student and evaluated the lesson. Then we analyzed points of teaching and learning in the lesson and improved the lesson plan. From the analysis, we found as follows. --The lesson has the framework that the teacher constitutes of four elements. --The teacher aims to make students build up its framework, but doesn't success. --In the lesson, students build up different alternative frameworks from its framework, think and discuss history according to these alternative frameworks and make new conception of history with teacher. --The teacher doesn't use these alternative frameworks well.