Abstract: The concentrations of zinc (Zn), copper (Cu), lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As) were determined by using various tissue or organs (e.g.liver, pancrea, stomach, kidney, intestine, lung, muscle, heart, skin and brain) of two Indo2Pacific humpback dolphins (Sousa chinensis) found dead in coastal water near Xiamen harbor in April, 2004. In general, essential elements Zn and Cu were accumulated at a higher concentration than toxic elements Pb, Hg, Cd and As in most tissues or organs of both dolphins.In animal XM20040430 particularly higher concentrations of Zn, Hg, Pb and Cd were observed in the skin (500μg/g dry weight), liver (255μg %g dry weight), lung (13.0μg/g dry weight), and kidney (2.82μg/g dry weight), respectively.In contrast, those of tissular Cu and As level were similar.In animal XM20040430 only hepatic Zn (448μg/g dry weight) and Cu (52.0μg/g dry weight) concentrations were much higher than those in any other tissue or organ. Although the concentrations of trace elements in two dolphins seemed not to cause acute toxicity, possibility of chronic impact cannot be eliminated as toxic Pb, Hg, Cd and As were detected evidently and hepatic Zn in the liver of animal XM20040429 showed an abnormally high level.It is notable that the contamination by Hg, Pb and Cd in Xiamen water has not been reduced in recent years based on comparison of our results with the accumulation levels in S.chinensis of the previous literatures.Effective toxic element pollution control strategies are necessary for future conservation of the endangered animals like S.chinensis and fishery species along Xiamen coastal water.In addition, As pollution in marine mammals of China requires further study.