This paper analyzed the correlation of heavy metals in sediment of Lianyungang sea area by the methods of variation coefficients, concentration coefficients and potential ecological risk indexes. The results showed that significant differences existed in spatial distribution and accumulation of heavy metals, the extent of spatial fluctuation was in order of Cu = Cd＞Hg＞Cr＞As＞Zn＞Pb, the extent of the accumulation was in order of Zn＞Cr＞Cd＞Cu＞As＞Pb＞Hg; The potential ecological risk of heavy metals to ocean ecology system was very slight except for Cd which was at middle pollution level found at 5 stations, the potential ecological risk was in order of Cd＞Hg＞As＞Cu＞Pb＞Cr＞Zn, the accumulation of heavy metals was serious and the potential ecological risk was high in port area; Organic carbon (DOC) and acid volatile sulfide (AVS) influenced the transport and transform process of heavy metals and then influenced the potential ecological risk level and biotoxicity.