We are anxious about fixing of an alien species Snapping turtle Chelydra serpentina in the park with the waterside. In Kanagawa Prefecture, the snapping turtle was breeding by Hikichigawa shinsui park Obayusuichi and Komatsugaike park and we conducted capture investigation from 2008 to 2012. We dissected the captured snapping turtle of 78 individuals, have grasped feeding habits from gastric contents, and compared with the habitat environment. Although most large-sized individuals have been exterminated because we continue capture for several years, many of small individuals were not able to be collected. We thought that american crayfishes and aquatic plants are main food for them. Not only extermination of the snapping turtle which has a possibility of inflicting harm on people, for the improvement in the health of the ecosystem of a water-front park but proper management of the visitor aquatic life and aquatic plant used as the food is important.