In order to elucidate the budget and cycling of Nitrogen and Sulfur, esential elements and principal constituents of acid rain, their input through precipitation, and their output by streamflow were quantified in coniferous and deciduous forested watersheds, using combination of nutrient concentration and hydrological analysis, in Kwangnung Experimental Forest from July 1991 to Decmeber 1993. Amount of annual mean precipitation was 12.916 ton·ha^-1·yr^-1, annual mean runoff 5,094 ton·ha^-1·yr^-1(39%), 7,647 ton·ha^-1·yr^-1(59%) in coniferous and deciduous forest watersheds, respectively. Amounts of annual input of N(NO₃^-+NH₄⁺) and SO^2-₄ through preciptation were 12.5, 81.7 kg·ha^-1·yr^-1, respectively. Annual output via runoff of N(NO₃^-+NH₄⁺) and SO^2-₄were 0.06, 39.23 ton·ha^-1·yr^-1 in the coniferous forest watershed ecosystem, and 0.15, 55.46 ton·ha^-1·yr^-1 in the deciduous one, respectively. On the basis of annual nutrient input and output, the annual budget of N(NO₃^-+NH₄⁺) and SO^2-₄were +12.46, +42.49 ton·ha^-1·yr^-1 in the coniferous forest watershed, and +11.35, +26.26 ton·ha^-1·yr^-1 in the deciduous one. Thus N(NO₃^-+NH₄⁺) and SO^2-₄were accumulated in both forested watershed ecosystems.