Yokkaichi site is post-town located in Saijo basin of Higashihiroshima city. Yokkaichi post-town was known to exist by illustrated houses map and historical records, specific aspects by excavation revealed. Though it is in the inland, a lot of marine products are excavated. In this paper, I report the characteristics of the excavated shellfish, to discuss the distribution of marine products in the post-town.As a result of the analysis, 16 kinds of shellfish have been identified, and the most was marine shellfish, and these species are also rare in the sites of the coastal areas. Features of shellfish composition is to occupy overall half in rock shell (Rapana venosa ) and horned turban (Turbo cornutus ), and to be followed by razor shell (Solen strictus ) and scallop (Pecten albicans). It can be pointed out to be different from the sites of Hiroshima Bay area in the feature of the shellfish composition. It is also a specific point that a lot of big rock shells are carried to the Yokkaichi site.The specificity of the excavated shellfish is a characteristic of post-town located in the inland area, and it is considered to indicate that the ingredients of the food to be provided to the daily diet of the people living there and travelers were different. Additionally, although in the literature has been left a record that ate the oysters of Kaita (Hiroshima Bay area) in the Yokkaichi post-town, the distribution route of seafood is likely to be Mitsu (current Akitsu area), because Mitsu Shou-okan starting from Mitsu to Saijyo Yokkaichi was used in those days.It was possible to report the interesting marine shellfish use in the early modern times post-town located in the inland.