The distribution and abundance of marine debris on 26 beaches along the Sea of Japan were investigated from September 1999 to November 1999. The mean concentration of stranded debris in Japan and Russia was 2, 808 and 1, 547g/100m2, respectively. The most abundant stranded debris was plastic that accounted for 40% to 80% of total items in terms of weight and number. The mean concentration of submerged debris in Japan and Russia was 19.9 and 8.04g/m2 respectively. Of the submerged debris collected, fragments of plastic products were the most abundant item in terms of weight, and styrofoam pieces numerically. The average ratio of submerged debris to stranded debris in weight was 0.74, which suggests the significance of submerged debris for evaluating the status of debris onbeaches. Plastic pellets that are the raw material of plastic industry were found on 17 Japanese beaches and one Russian beach.