The aim of this study was to clarify the effect of the action research type training in a master's course stage, especially focusing on two knowledge: "teacher's practical knowledge" and "teacher knowledge about pedagogy". As a result, two points were made clear.
1. Throughout the action research type training, simplex knowledge about "teacher's practical knowledge" was greatly seen in the graduate students in a master's course, similar to the prior research. Plus, "Teacher knowledge about pedagogy" was also seen in the action research type training.
2. Throughout the action research type training, graduate students in a master's course changed its' multiple "teacher's practical knowledge" and "teacher knowledge about pedagogy" by receiving mentoring from a faculty member, supervisor, and mentor.