Kim, Bu-Yeon This study aims to understand the theory of didactic transposition and to analyze textbooks which contain transformed knowledge, with a view to knowing various possibilities of the transposition of knowledge. Education about the history of Korean language, which is a sector clearly characterized by knowledge among Korean language textbooks, is appropriate for an examination of how academic knowledge has been changed into teachable knowledge. This study compares the contents of the history of changes of Korean language in authorized textbooks in terms of didactic transposition, so as to investigate how academic knowledge and knowledge presented in curriculums has been changed by authors of textbooks into teachable knowledge. It is expected that this study will be subservient to moving ‘knowledge of the history of Korean language which is to be taught in school grammar’ in a right direction.