An agricultural land application of swine slurry is one of the best management practices in Jeju island whose ground water must be protected. So as to study the effect of appling swine slurry on ground water or aquifer, incubation-leaching technique was used by assuming the incubating period of 1, 2, 4, 8, 16, or 32 days, and application rate of 3200.0 mgT-N/$ell$ , 820.0 mgT-P/$ell$, and 1887.0 mgK$^$+/$ell$ in swine slurry. The leachates were collected from the soil columns(PVC 30 cm L${ imes}$5.5 cm D) packed 15cm in depth with Gangjeong soil series by washing with 100 mL distilled water. The leached components were measured by using ion chromatography far Cl$^$-/, NO$_3$-N, F$^$-/, Br$^$-/, Na$^$+/, K$^$+/, Ca$^2$$^$+/, and Mg$^2$$^$+/ , atomic absorption spectrophotometry for Fe and Mn, and UV-Vis spectrophotometry for T-N and T-p. Application of swine slurry in naked soil could influence on the ground water or aquifer by increasing nitrate-nitrogen in leachate with time, or leaching the cations present in soils in accompany with anions because of H$^$+/produced in nitrification. Therefore, careful consideration should be taken about what amount, when, where, and how fur protecting ground water system.