摘要:Two sampling stations which are 10 km and 50 km distant from the estuary of a tidal river (The River Naka) were prepared. The contents of samples taken at the stations were analysed 22 times from May 1964 to Feb. 1966. The relation between the contents in the river water and geographical features, and between water temperatures were investigated. The following results are obtained. 1. Under the same atmospheric condition, the turbidity and suspended solid in the river water among the mountains are more variable than those at the plain, since the year. On the other hand, the concentration of Cl ion and BOD value in the river water at the plain are more variable than those among the mountains. It is supposed that the component in the river water are influenced by circumstances of the river basin. 2. The suspended solid and turbidity in the river water are related to the water level. The dissolving oxygen content in the river water has correlation to the water temperature.