The purpose of this study was to investigate the sources and characteristics of city nonpoint pollutant and also provide the basic data for proper management plans of nonpoint pollutant by using the results to analyze heavy metals and organic matter from the major roadside sediment. Total 20 samples from the roadside sediment were collected in Gwangju City during April and August in 2010. The results of pH were ranged from 6.8 to 9.3, slight alkalinity generally. Average concentrations of heavy metals were 336.861 mg/kg for Zn, 98.377 mg/kg for Cu, 58.406 mg/kg for Pb, 32.153 mg/kg for Ni and 0.583 mg/kg for Cd. The case of Hg and As were similar to natural abundance. Average concentration of Ni, Cu and especially Zn increased during April and June which is called the yellow sand season, but decreased during July and August, which is called the rainy season. Average concentration of organic matter were 5782 mg/kg for CODcr, 82.72 mg/kg for T-N and 282.29 mg/kg for T-P. The correlation analysis among heavy metals, showed that the correlation between Cu and Cd was highest (0.75, P<0.01) and also there were significant correlations among Cu - Ni, Zn - Ni, Zn - Pb and Zn - T-P. In addition, geoaccumulation index indicated the Igeo-class of Cu was ``very strongly polluted``, Pb and Cd were ``strongly polluted``, Zn was ``Moderately/strongly``.