Abstract: Coastal area of Makassar City spread out of ± 35km. This area is susciptible on various polutants resulting from some activities both naturally and mostly antropogenic. The existing of industrial, agricultural, hospital wastes and gold processing enteprise were the main potential source of Mercury (Hg) in form of metal and vapor through waste disposals. This study aimed to investigate the concentration of mercury (Hg) on sea water, mollusk Marcia Hiantina and urine of molusk seekers and the potential environmental risk posed in coastal area of Makassar.