Precipitation samples were collected at the GAW Stations in Anmyeon-do and Gosan for 10 years (2008-2017) to analyze pH, electrical conductivity and NH4+, Na+, K+, Mg2+, Ca2+, SO42-, NO3-, Cl-, and F- ions. From the analysis, the correlation between pH and rainfall, the composition of precipitation and comparison with other regions, and the results of neutralization characteristics by seasonal and pH were determined. In the comparison of ion balance and conductivity for the validation of analytical data, the correlation coefficients were within the range of 0.996~0.999, implying good linear relationship. The volume-weighted pH of the Anmyeon-do and Gosan areas were 4.7 and 4.9, respectively. The pH of the rainfall was affected by washout and rainout in both areas. The ionic strength of precipitation at Anmyeondo and Gosan were 0.42 ± 0.63 mM and 0.37 ± 0.75 mM, indicating about 27.6% and 35.3% of the total precipitation as per a pure precipitation criterion (10-4 M), respectively. The composition ratio of ionic species were 44.7% and 57.5% for marine sources (Na+, Mg2+, Cl-), 40.6% and 22.2% for the secondary inorganic components (NH4+, nss-SO42-, NO3-), and 5.6% and 4.0% for the soil source (nss-Ca2+), respectively. The neutralization factor of Anmyeon-do and Gosan were 0.43~0.65 and 0.34~0.48, and the neutralization factors of calcium carbonate were 0.15~0.34 and 0.25~0.30, respectively. Thus, both regions have the highest rate of neutralization caused by ammonia. As pH increased in Anmyeon-do and Gosan, change in calcium carbonate became greater than that in ammonia.