Heavy metals (Pb, Cd, Cu, Mn, Ni and Zn) were determined in surface sediment, mussel (Mytilus galloprovincialis) and short-necked clam (Ruditapes philippinarum) collected from Maizuru Bay, a semi-enclosed marine inlet of the Japan Sea, in 2007 in order to elucidate their contamination levels and distribution. The highest Pb concentrations in sediments, mussels and short-necked clams, 8716μg/g dry, 131±56μg/g wet, 579±459μg/g wet, respectively, were detected in samples from the lead battery recycle factory basin. These evaluates are the most inferior level applied to the environmental index and food-safety standard. Relatively higher Cu. Mn and Ni concentrations were noted in the sediment samples from the factory basin. Considering these results, the ability of lead highly concentrated in surface sediment, mussel and short-necked clam poses a direct threat to the marine ecosystem and mankind. Continuous monitoring and investigations on the effect of Pb are especially needed in Maizuru Bay.