The purpose of this article is to classify dialect words related to fish names into two types of "Used" and "Not Used" from the viewpoint of comparison between the eastern region and western region of the Oshima Peninsula and to specify similarities and differences of their forms, meanings, referents, ways of use and some information to note. All the dialectal fish names are collected through the field-work in Todohokke, an area on the east coast, and in Setana, a town on the west coast of the peninsula. The comparison study will reveal what creates a variety of fish names in dialect and how they are produced.学術論文