This study deals. with historical investigation on the physical training activities of the youth groups, called "Seinen-Kai" (youth association) or "Seinen-dan" (youth corps), in Hiroshima Prefecture during the Meiji and Taisho periods. Their main features would be summarized as follows; 1. There were no recognizable physical training programs in the activities of the youth associations in the early stages. 2. The youth associations began to adopt physical training programs from about 1905, when the Japanese government turned to encourage organization of youth associations. Their purpose was for amusement, rather than physical training itself. 3. Since 1915 when the government-sponsored youth associations (the so-called "Kansei Seinen-dan") were organized, emphasis on physical education in the Seinen-kai turned to be more agressive, harder training. 4. From about 1920 and on, the physical training of youth corps began to focus on athletic contests. This trend climaxed at the national athletic contest held at the Meiji-Shrine athletic ground, which clearly reflected the nature of physical training in the youth corps. 5. Generally speaking, the physical activities of youth groups tended to focus on big events, rather than on daily training, and their interests were kept concentrated on occasional athletic meetings or conventions.