The purpose of this thesis is to clarify one side of Japan in modern times by analyzing methods of body fitness. First of all, I study the background of the time when various body fitness methods were very popular among people. Secondly, I pick up three of the fitness methods-the Okada method (Okadashiki Seizahou), the Kawai method (Kawaishiki kyoukenjyutsu), the Nishi method (Nishishiki kyoukenjyutsu) -and study the differences in the theories and fully exercised bodies of each method. And lastly, from the comparison with physical education, I examine the process that how the modernization of their bodies spread among people in Japan.