In order to understand chemical characteristics and formation of dewfall in Busan, we analysed monthly distribution of dewfall, and investigated its chemical composition of dewfall. This study used the modified teflon plate (1m × 1m) at Jangyongsil science high school from June 2005 to October 2005. In order to estimate qualitatively water soluble components, IC, ICP and UV methods for water soluble ions are also used respectively. Dewfall amount of sampling periods (26 day) collected 1.29 ㎜. Distribution of water soluble ions in dewfall founded the highest concentration (81.3 μeq/ℓ for NO3-, 146.6 μeq/ℓ for SO42-, and 114.3 μeq/ℓ for nss-SO42-) during the June. pH was the lowest by 5.12 June, and October (pH 6.68) by most high and average pH was 5.46. Monthly equivalent ratio of [SO42-]/[NO3-] showed the highest value (2.94) during the September, the lowest value (1.77) during the July, and the mean value was 3.45.

In order to understand chemical characteristics and dewfall formation in western Busan area, we analysed monthly distribution of dewfall, and investigated the correlation between dewfall formation amount and meteorological factors. This study used the modified teflon plate (1m×1m) at Silla university in Busan from August 2002 to April 2003. In order to estimate qualitatively water soluble components, IC, ICP and UV methods for water soluble ions are also used respectively. Dewfall amount of sampling periods (47 day) collected 3.8 ㎜. Meteorological conditions for the formation of dewfall above 50 g/m2 showed that temperature diurnal range(℃) was 5.6℃ above, cloud amounts (1/10) at dawn of the sampling day was 7/10 below, mean wind speed at dawn (0～6hr) of the sampling day was 4.4 m/sec below, and mixing ratio at 6hr of the sampling day was 3.2 g/kg above. Distribution of water soluble ions in dewfall founded the highest concentration (206.1 μeq/ℓ for SO42-, 42.4 μeq/ℓ for NH4+, 249.2 μeq/ℓ for Ca2+, and 42.0 μeq/ℓ for Mg2+) during the March, the lowest concentration (73.0 μeq/ℓ for SO42-, 4.6 μeq/ℓ for NH4+ and 72.7μeq/ℓ for Ca2+) during the August. Monthly equivalent ratio of [SO42-]/[NO3-] showed the highest value (4.99) during the October, the lowest value (1.84) during the August, and the mean value was 3.45.