Long-term passive diffusive samplers(PDS) have been used to measure $NO_2;and;SO_2$ concentrations at 21 sampling sites in Daejeon, Korea during the period of January 2000 - December 2002. The spatial distributions of annual $NO_2;and;SO_2$ concentrations were mapped. Average annual $NO_2$ concentration over the sampling period was $28.5{pm}12.5;ppb$, ranging from 1.2 to 81.7 ppb. Average annual $SO_2$ concentration over the sampling period was $7.7{pm}4.8;ppb$, ranging from 0.6 to 26.8 ppb. On average, $NO_2$ concentration was approximately 5.8%(1.6 ppb) larger in 2002. $SO_2$ concentration was decreased by 13%(1.1 ppb) during the sampling period. The seasonal variation of $NO_2;and;SO_2$ concentration was observed with a tendency to be higher in fall and winter. $NO_2;and;SO_2$, concentrations measured at different site types(patterns of land use) show significant difference. The observed difference in concentration was associated with difference in emissions of $NO_2$ from motor vehicles and $SO_2$ by non-traffic fuel consumption for heating.