The vertical distribution of freshwater planarians in Kyoto City and the adjacent district in the northern part of the Kinki Region in Honshu (Lat. 34°40′N. to Lat. 35°30′N. and Long. 135°25′E. to 136°15′E.) is reported. The City is situated in the central part of the Kyoto valleys (a basin watered by the Yodo River system). The northern part of Kyoto City and Kameoka City are characterized by hills and low mountains (the highest peak, Mt. Buna in the Hira Mountains, is 1214 metres above sea level). Lake Biwa-ko, the largest lake in Japan, is located in the north-eastern corner of the area surveyed at an elevation of 86.3 metres. Biwa-ko has a 235 kilometres long shoreline, and a maximum depth of 102 metres. The main river systems of the area surveyed are the Katsura, the Hozu, the Oi, the Kamo, the Takano, the Uji and the Ado (tributaries of the Yodo River) and the Ono (the upper part of the Yura River). The Yodo River discharges into Osaka Bay facing the Pacific Ocean. The Yura River discharges into the Sea of Japan. The surveys were made from 1950 to 1966. In the vicinity of Kyoto City, four species of freshwater planarians, Dugesia japonica ICHIKAWA et KAWAKATSU, Phagocata vivida (IJIMA et KABURAKI), Phagocata kawakatsui OKUGAWA and Bdellocephala brunnea IJIMA et KABURAKI, were found. D. japonica was most common in the stations both in the plain and the mountainous districts (below the altitude of about 950 metres). Ph. vivida was rather common in the cold-water stations within the altitude range from about 120 to 950 metres or more. Ph. kawakatsui was found only in a-spring-fed stream in Kameoka City (Asahi-cho ; the type locality of this species) and in a shallow well at Saga-tenryuji-cho in Kyoto City. A small population of Bd. brunnea was found in a large spring-fed stream at Nishioji-sichijo in Kyoto City (the southernmost locality of this species). This station is well known to biologists as the locality of the sexual race of D. japonica (the Nishioji stock). The type of the vertical distribution in the area surveyed is shown as J-JV-V (J : D. japonica ; V : Ph. vivida). The two species of true lake-dwelling triclads, Bdellocephala annandalei IJIMA et KABURAKI and Dendrocoelopsis ? sp. of Lake Biwa-ko, were recorded from the muddy bottom (35 to 50 metres or more in depth) of the middle and northern parts of Lake Biwa-ko. Figure 2 shows the distribution of the planarians in the lake (revision of the KAWAKATSU's 1964 map).