This study aims to clarify what factors made and transformed‘teaching style’ in physical education of Elementary School Teacher A through interpreting a life history of Teacher A. The results are summarized as following points. 1. The ‘teaching style’ of Teacher A on physical education in the I period (1982.4-1987.3) was made by factors of ‘belief as a teacher’ and ‘school tradition of Attached Elementary School B and chances of professional development’. 2. The ‘teaching style’ of Teacher A in the II period (1987.4- 1991.3) was transformed by factors of ‘meeting with Mr. Toshio Nakamura belonging to Gakko Tiiku Kenkyu Doshikai’ and ‘anxiety of lack of the specialty concerning physical activities’. 3. The ‘teaching style’ of Teacher A in the III period (1991.4-1996.3) was transformed by factors of ‘his reflection about his specialty on teaching movement skill’ and learning of a concept of ‘observation of others’ and ‘self-observation’ concerning movement process in "Bewegungslehre-Sportsmotorik" (Kurt Meinel et al., 1987). 4. The ‘teaching style’ of Teacher A in the IV period (1996.4-2003.3) was transformed by factors of influences from educational content theory by Mr. Yasuaki Izuhara belonging to Gakko Tiiku Kenkyu Doshikai.