Surface sediment and biota were collected from 12 sampling sites - seven along the Pearl River Delta and five along the Hong Kong coastline. Perfluorinated compound (PFC) concentrations were detected using a high-performance-liquid-chromatogram-tandem-mass-spectrometry system. Analytical results indicated that the total PFC concentrations were in the range of 0.15-3.11 ng/g dry weight in sediments, while the total PFC concentrations in oyster and mussel samples were between 0.46-1.96 and 0.66-3.43 ng/g wet weight, respectively. The major types of PFCs detected in the sediment samples were perfluorooctanesulfonic acid (PFOS) and perfluorobutanoic acid (PFBA), with concentrations ranging from low limits of quantification to 0.86±0.12 ng/g dry weight and 1.50±0.26 ng/g dry weight, respectively. In bivalve samples, PFOS was the dominant contaminant with concentrations ranging from 0.25±0.09 to 0.83±0.12 ng/g wet weight in oysters and 0.41±0.14 to 1.47±0.25 ng/g wet weight in mussels. An increase in PFC concentration was found to be correlated with increased human population density in the study areas.