The author, who is studying the development of water-power utilization in Japan from a standpoint of historical geography, analysed, in former articles (in the Human Geography, vol.19, No.5, 1967, and others), the situation of water-power utilization in Nara Prefecture in the so-called water-mill age. According to his conclusions, water-mills were mainly distributed in the villages of the Yamato Plateau, north-eastern part of the Prefecture, and gathered in some towns and villages of the Nara Basin, north-western part of the Prefecture (fig. 1). These water-mills were usualy used for rice-cleaning, flour-milling, oil-pressing, cotton-ginning, spinning and so forth.In Japan, the first hydroelectric power station was built in 1892, and after that the new era of water-power utilization was inaugurated. Thirteen years later, namely in 1905, the first project of hydroelectric power station, whose plan was to harness the River Yoshino, was started in Nara Prefecture. After this planning, many projects rushed in the Prefecture, especially on the rivers of Totsu, Kitayama, Yoshino, in southern part, and on the rivers of Uda, Nabari, Hase, in northern part. According to the application-list of these early projects which were applied to the prefectural government during 1905 to 1918, almost all were channel type power stations, which are shown in fig. 2 by arrows and black figures.Even if only 32 projects were realized among these early 97 projects, it may be noticed that the distribution pattern of hydroelectric power schemes in Nara Prefecture was much different from that of old-time water-mills, as we can see in comparison of fig. 1 and fig. 2. Also in the Yamato Plateau district, where the water-power was intensively exploited through the periods of water-mill and hydroelectricity, similar difference of patterns is discerned distinctly. In this Yamato Plateau district, water-mills used to be built in the villages which were situated on this plateau, while electric power stations were constructed on the marginal scarps of the plateau, where rivers, such as Hase, Shirasuna, Nunome, flowed down torrentially (fig. 3). By the characteristics of this regional pattern, any conflict didn't occur between the traditional system of water-power utilization and the new-born system of hydroelectric power schemes.