In this paper, it paid attention to the runoff coefficient corresponding to the land-use patterns that became one index when the rain water outflow was understood. The runoff coefficient corresponding to the land-use patterns is presumed by counting backward of the weighted average of the land-use area rates. At that time, the runoff coefficients where the catchment is assumed to be the same land-use is necessary. Therefore, they were presumed by comparing the flood analysis result with the water level observation setting up in the major channels. When this runoff coefficients corresponding to the land-use patterns were applied to another catchment, 26% of bound pair value in indicators was the difference between them with the runoff coefficient presumed by comparing two. As a result, it is considered that this proposal method of presuming the runoff coefficients is appropriate.
