Precipitation samples were collected for a total of 10 years from 2011 to 2020 at the GAW Stations in JejuGosan and Ulleung-do. The analysis results of pH, electrical conductivity and 9 ion(NH4+, Na+, K+, Mg2+, Ca2+, SO42-, NO3-, Cl-, and F-) components were compared with other regions, and acidity and neutralization characteristics of the pH section, and pollutants were analyzed. The volume-weighted average pH of precipitation components in JejuGosan and Ulleung-do was weakly acidic, and the electrical conductivity was 21.9 and 48.5, respectively, which was about 2.2 times higher in Ulleung-do. In the case of pH, both regions showed similar chemical composition concentrations as those of Hawaii, Bermuda, and the Philippines, but showed lower values than those of Hallasan 1100 in Jeju Island and Taiwan, Sri Lanka and Samoa. The SO42-component showed similar or slightly lower concentrations of JejuGosan precipitation than the Hallasan 1100 highlands, Taiwan, and Bermuda, but the concentration of Ulleung-do precipitation was about 1.4 to 5.1 times higher. As a result of the pAi (Potential Acidity) of precipitation in both regions, nss-SO42- and NO3- components exist in the form neutralized by other cations (except H+) in the precipitation. Precipitation from JejuGosan had a higher neutralization factors by ammonia than precipitation from Ulleung-do, but precipitation from Ulleung-do had a higher neutralization factors by calcium carbonate than precipitation from JejuGosan. The pollutants of precipitation collected over the past 10 years on JejuGosan were most affected by sea salt and biomass. On the other hand, Ulleung-do was affected by sea salt, ammonium sulfate and ammonium nitrate. As a result of back trajectory analysis, JejuGosan showed a high concentration of major components when air moved from China. The Ulleung-do region showed a high concentration of major components when air was introduced from two regions ((1) China and the Korean Peninsula, and (2) Russia region).