For a long time, shellfish is considered as one of important item in the human daily food resources. In 1977, Professor Li Kuangchou has carried out archaeological excavation at Kenting site. This paper, of shellfish remains from the site of Kenting, southern Taiwan, provides the pattern of shellfish gathering which was conducted by the prehistoric population inhabiting Kenting 4000 years ago. In total, 24 families, 43 species of shellfish can be identified in the archaeological remains. Shells have the highest frequency with turban shells, vases, cowries, cones, and giant clams playing the most significant role. Stable isotope ratios of carbon and oxygen in shellfish have been determined for turban shells and nerites, venus clams, arks, tellins from archaeological excavated unit. The δ^13C andδ^18O records of shells indicated that these mollusks inhabited in an open sea environment and river mouth area and were mostly collected between summer to winter time. The prehistoric water environment was not much different from the modern one. Geological changes around the mouth of Shih-niu stream was proposed as the reasons for dramatic decrease of some mollusce in the modern time period.