Abstract: According to the on-site monitoring data of shellfish culture area in Lianzhou Bay in August from 2012 to 2017, the contents of heavy metals (Hg, Cu, Pb and Cd) in seawater and surface sediments were discussed, and the pollution status of heavy metals in two media and potential hazards of heavy metals in sediments were evaluated. The results showed that the average contents of heavy metals in seawater were Cu> Pb> Cd > Hg. The inter-annual variations of Hg, Pb and Cd all showed an obvious upward trend except for Cu. The pollution level was Cu> Hg > Pb> Cd while the overall water quality of heavy metals was basically at the background level. The average contents of heavy metals in surface sediments were Pb > Cu> Cd> Hg. The inter-annual variations of Cu, Pb and Cd were basically the same as those in the aqueous phase except for Hg. The pollution level was Cu > Pb > Hg > Cd while the overall pollution level was medium. The potential ecological risk level of heavy metals in surface sediments was Hg > Cd > Cu> Pb and the synthetical potential ecological risk index RI was less than 140 with an average 76.98 from the results of 6 surveys. It indicates that the area was in the state of low potential ecological risk level.