Abstract: Based on the results of 14 stations in the coastal sea of Tianjin, we analyzed the content and distribution characteristics of 7 heavy metals (Cu, Pb, Zn, Cd, Cr, Hg and As) in surface sediments, evaluated the environmental quality of heavy metals in sediments by the potential ecological risk index method and consistent sediment quality standards, and used multivariate statistical analysis to analyze the sources of heavy metals. The results showed that the contents of Pb, Zn, Cd, Cr and Hg in the surface sediments were all in accordance with the first class of marine sediment quality standards, and only Cu and As exceeded the standards at a few stations; the contents of heavy metals were higher in the central and southern waters and lower in the northern waters from the spatial distribution; except for Hg, which had a moderate to strong potential ecological risk, the other heavy metals in the surveyed waters were all in the slight grade. As and Cr were above the lower threshold for heavy metal toxicity effects at some stations but did not exceed the upper threshold, while the remaining heavy metals were below the lower threshold for heavy metal toxicity effects, indicating that the probability of sediment heavy metal toxicity hazards in Tianjin coastal sea was low. The elements Cu, Pb, Zn and Cr in the sediments were probably mainly derived from natural processes, while As and Cd were mainly derived from human industrial and agricultural activities.