Dry deposition of particulate matter, organic carbon and PAHs (Polycyclic Aromatic Hydrocarbons) were measured at two stations in an urban area. While the deposition fluxes of particulate matter and POC were nearly constant, those of PAHs had seasonal variability. The inflow flux into a combined sewage treatment plant at this area was also measured during non-rainy and rainy periods, respectively. Diurnal changes in water discharge, particulate matter and PAHs were observed during each of the non-rainy periods, thereby suggesting diurnal cycle of human activity. The first flush phenomena that is faster runoff of particulate matter and PAHs than water discharge were clearly observed at all the rainy periods. Although their PAHs contents agreed fairly with those of dry deposition, their fluxes were a few times larger than those of dry deposition.