This study aims at clearing that the change of Seki's interpretation of Garden City Theory from his period of professor to the period of deputy mayor of Osaka city. Seki was interested in the Garden City movement in European countries from the aspect of labor issues when he was the professor of public policy at the higher commercial school. He interpreted that there were three types of Garden City Theories, which were “Garden City”, “Garden Suburb” and “Industrial Village”, from the period of the professor. However he didn't have clear images for each type of theories. Since he became the deputy mayor of Osaka city, his interpretation of Garden City Theory had been changed through his continuous study of Garden City Theory and through his position, which he had to practice his public policy at Osaka city.
In 1919 and in 1921, He wrote some newspaper articles about Garden City. He mentioned “Garden City” and “Garden Suburb”, and he equated “Garden City” with “Garden Suburb” in his articles. However, in 1922, he published three articles and mentioned “Garden City” and “Garden Suburb”, he tried to differentiate “Garden City” and “Garden Suburb” in his articles. He explained the difference between “Garden City” and “Garden Suburb” as follows the points are the necessity of agricultural area and the necessity of self-sustainability. In fact, he insisted that “Garden City” meant self-sustained city, which held the agricultural area for serving the inhabitants living in the city. On the other hand, “Garden Suburb” meant dependent city on the big city, which did not hold the agricultural area. In addition, he insisted that “Garden City” theory was based on Ebenezer Howard's theory and “Garden Suburb” theory was based on Raymond Unwin's theory.
From this study, it becomes clear that he suggested the importance of “Garden Suburb” theory and “Industrial Village” theory to Osaka city since 1922. The reason of this, his idea of urban extension plan for Osaka city aimed not at creating another city but at extending Osaka city for taking in the population that had been growing and for supplying especially working classes and lower classes with sanitary houses. His both ideas of “Garden Suburb” theory and “Industrial Village” theory were built up and were connected to the theory of “Satellite City”, which he meant the decentralization of industry, population and housing.
