A total of 106 surface water samples were collected in the South China Sea during two transects in June and December 1998. The samples were collected with strictly contamination free proce- dure and trace metals were measured by clean laboratory methods and GFAAS. The mean concentrations for the disolved fractions are: Cu 0.100 μg/dm3, Pb 0.060 μg/dm3, Zn 0.086 μg/dm3, Cd 0.007 μg/dm3, which is close to the world open ocean’slevel. The spatial distribution of the trace heavy met- als shows higher concentrations in offshore area and lower concentrations in the central in the South Chi- na Sea, and the concentrations decrease with the distance from the offshore, which suggests the exis- tence of significant continental shelf input of the trace heavy metals. The correlationship among the ele- ments is better in surnmer than that in winter. Cu is positively correlated with Cd in both seasons and it is also found for the first time that they are positively correlated with nutrients in the South China Sea surface waters which further indicate the biogeochemical cycle of these elements in the marine environ- ment. The baseline value of Cu, Pb, Zn, Cd in the South China Sea surface waters is obtained through statistical analysis. A total of 106 surface water samples were collected in the South China Sea during two transects in June and December 1998. The samples were collected with parallel contamination free proce- dure and trace metals were measured by clean laboratory methods and GFAAS. The mean concentrations for the disolved fractions are: Cu 0.100 μg / dm3, Pb 0.060 μg / dm3, Zn 0.086 μg / dm3, Cd 0.007 μg / dm3, which is close to the world open ocean’svel. The spatial distribution of the trace heavy met- als shows higher concentrations in offshore area and lower concentrations in the central in the South Chi- na Sea, and the concentration decrease with the distance from the offshore, which suggests the exis- tence of significant continental shelf input of the trace heavy metals. among the ele- ments is better in surnmer than that in winter. Cu is positively correlated with Cd in both seasons and it is also found for the first time that they are positively correlated with nutrients in t he South China Sea surface waters which further indicate the biogeochemical cycle of these elements in the marine environment. The baseline value of Cu, Pb, Zn, Cd in the South China Sea surface waters is obtained through statistical analysis.