Both stagnant and flowing water conditions in the Kinokawa river, a number of phytoplankton and their species were analyzed. The number of blue-green algae increased with both water temperature and decreasing water flow. As the river flow rate decreased in summer season, the ratios of Merismopedia sp. in blue-green algae, Nitzschia sp. in diatom, and Scenedesmus sp. in green algae increased. In summer season Nutrient in the Kinokawa river decreased with flowing and then nutrient in the middle stream of the Kinokawa river decreased because of decreasing flow and increasing phytoplankton.
