Non-point source pollutant is exerting a serious influence on the water quality, since the characteristics of
stormwater runoff is varied by the land usage pattern of an area and a basin, and all sorts of pollutants on the
earth in rainfall flow into the urban stream. This study estimated EMC of each pollutant to investigate the
characteristics of stormwater runoff by separating the urban area as the housing area and industrial area. As a result
of the analysis, the first flush effect occurred in the non-point source pollutant of housing area and industrial area,
as the runoff concentration gradually reduces after it rapidly increases in the initial rainfall, and in case of the
non-point source pollutant the control of first stage rain-water. It is considered to require the continuous follow-up
study such as the scale of long-term rainfall event and water quality data, land usage pattern by GIS method,
database of topography and geological features, and so forth.