A wave-induced erosion of a sea cliff may cause a cliff failure and a resultant large-scaled disaster. In order to simulate this kind of phenomenon, a formation process of notch due to repeatedly acting waves must be tracked by the analysis of stress in a sea cliff. In time-dependant large-deformation analyses, a particle method shows an excellent performance. In this study, a numerical simulation on a wave-induced erosion process of sea cliff is carried out by using a fluid-elastoplastic hybrid particle method with scouring model. Calculated results on a deformation of sea cliff are compared with previous experimental ones.