This study was conducted to reveal the vertical distribution and concentration variation of heavy metals（Cr, Co, Ni, Cu, Zn, As, Cd and Pb） in the mangrove sediments of Dongzhai Harbor, Hainan by using inductively-coupled plasma mass spectrometry（ICP-MS）. The surface sediment samples were collected from 15 sites, and a geoaccumulation index（Igeo） was estimated to quantify the pollution status of the mangrove sediments. The results showed that the concentrations of heavy metals in sediments followed the order of Cr〉 Zn〉 Ni〉 Cu 〉Pb 〉Co〉 Cd. A common pattern was found in some heavy metals（Cu, Zn, As and Pb） as their concentrations were significantly and negatively correlated with depth. Cr concentration in upper layer was slightly lower than that in middle and lower layers,while the concentrations of Ni and Cd in middle layer were slightly higher than in upper and lower layers. The geoaccumulation index indicated that the surface sediments at sites QT-1-01, QT-1-02, QT-2, GN-1, GN-2 and GN-3 were strongly polluted by Cd, and unpolluted to moderately polluted or moderately polluted by As.
