The study examined marine invertebrates (polychaetes, amphipods, decapods and molluscs) living in Goseong-gun, Gangwon-do. The study selected regions among the Goseong-gun waters including a high level of marine invertebrate diversity, and 4 sessions were conducted between March and September of 2010. As a result, 154 species of 68 families of marine invertebrates were observed, and the figure also included 11 unrecorded Korean species. The 154 marine invertebrates species observed in this study was added to the 188 species which were recorded in taxa encyclopedia to have been collected in Goseong-gun, thereby leading to 311 species of 99 families of marine invertebrates (polychaetes, amphipods, decapods and molluscs) living in Goseong-gun to be included in the inventory created.