This study aims to clarify regional aspects built by supporting systems of the sports industry through the establishment of prefectural branches of the National Physical Training Association. This study examined, 1） the process of establishment of prefectural branches, 2） the actual conditions of establishment as seen from the observation of the IBARAKI Physical Training Association, and clarified the following aspects. <br> 1） The National Physical Training Association promoted the establishment of the prefectural branches through the enactment of Article 14 of official branch regulations and examples of branch rules. The establishment of prefectural branches was a matter of priority for the National Physical Training Association, but the prefectures were pessimistic due to confusion related to organizational structure and financial aspects. The National Physical Training Association had approved the establishment of the prefectural branches, except the Tokyo and Toyama prefectural branches, by March 31, 1943. However, as the National Physical Training Association rushed the establishment of prefectural branches almost all of them have the date of establishment as later than the date of approval. Contrary to the impatience of the National Physical Training Association, the enthusiastic activities of the prefectural branches were different depending on the prefectural branch.<br> 2） In addition to the educators, the IBARAKI Physical Training Association was composed of stakeholders such as the military and police and the Imperial Rule Assistance Association. The management of the IBARAKI Physical Training Association had been funded by the contributions of these affiliates. Further, the IBARAKI Physical Training Association planned holding training meetings and the development of guiding.<br> As mentioned above, the National Physical Training Association tried to build a nationwide network grid system through the establishment of the prefectural branches. The prefectural branches strengthened the system through the close relationships with the affiliated organizations such as the military and the Imperial Rule Assistance Association. It can be said that such a construction of a regional level supporting system of the sports industry, the educators and educational institutions had a certain amount of influence.