Abstract: The concentrations of heavy metal elements (Hg, As, Cu, Pb, Cd, Zn and Cr) in the surface sediments were investigated on the continental shelf off the Pearl River Estuary in November 2017. Based on the field data, the sediment environment was evaluated using single factor standard index and Geo-accumulation index. Further, quantitative assessment on the potential ecological risk of these heavy metals was performed using the Hkanson index. The dominant sources were also determined with Pearson correlation analysis and principal component analysis. The results demonstrated that 7 heavy metals in all samples met the national firstclass standard of marine sediment quality. Overall, the environment of surface sediments was generally clean but slightly polluted by As (5.8% stations) and Cd (17.3% stations) according to the geoaccumulation index. Relatively low potential ecological risk was observed in the study area with RI value lower than 150. The potential ecological risk measured by single factor ranking from high to low was Cd>Hg>As>Pb>Cu>Cr>Zn. The potential ecological risk for Cd was medium (41.31) in the western areas. We also found that sources of Cr, Cu and Zn were similar and potentially from industrial and terrestrial pollutants. Pb, As and Cd were derived from pollutants from inland, marine transportation and agriculture. However, the sources of Hg showed little relationship with other heavy metals.