River flow regime is important role in determining the river morphology, water use and biotic composition. In Japan, however, river management based on the concept of variation of flow regime is not taken. Because the knowledge of potential hydrological regime is lacking. In this study, we proposed the flow regime indicators which can explain seasonal change of stream flow at 52 watersheds in the Kyushu region. And, we investigated the relationship between flow regime indicators and factors that affect the hydrology (physiographic factors, geological factors and vegetation factors). Result of multiple regression analysis, flow regime indicators were well explained by the factors of physiography, geological and vegetation. The results indicated that geology of volcanic ejecta tends to stabilize the flow fluctuation, and urbanization and plantation tend to increase frequency of disturbance and drought.
