The Nakayama Shell Midden site dates from the Final Jomon to the Middle Yayoi period, and is located in the vicinity of Hiroshima City, Hiroshima prefecture. Artifacts excavated from this site are known as “Nakayama-style pottery”, and are representative of this time period. Here, we report on the Nakayama I type pottery of the first half of the Early Yayoi period, and present a plan for subdividing it into classes. This classification scheme makes it possible to understand the nature of the transition from the Nakayama B type pottery of the Final Jomon, to the Nakayama II type pottery of the latter half of the Early Yayoi period, suggesting a temporal and successive continuity.