The chemical characteristics of precipitation was investigated in Pusan area. Samples were collected from January to November in 1996 at 4 sites, and analyzed pH, mayor soluble ionic components(Cl^-, NO_3^-, SO_4^2-, Na^+, K^+, NH_4^+, Mg^2+, Ca^2+).
The order of anion and cation concentrations for the initial precipitation were Cl^- > SO_4^2- > NO_3^- , and Ca^2+ > Na^+ > NH_4^+ > Mg^2+ > K^+, respectively. At coastal sites(P1 and P2) Cl^- and Na^+ of maritime sources (seasalt) were high, but at inland sites(P3 and P4) nss-Ca^2+ and nss-SO_4^2- were high. Calcium ion for the initial precipitation showed high value of enrichement factor(EF) relative to seawater composition. The contribution of seasalt to the composition of precipitation was higher at site P1 (53.5%) than those of the other sites. Throughout the year the concentrations of major ions for the initial precipitation were low in the heavy rain season. The mean pH for the initial precipitation was 5.4 and showed the negative relationship with the precipitaion amount. The SO_4^2- and NO_3^- do not play an important role in rain acidification due to the high(97%) neutralizing effect of amonia and calcium species.