A 3D FEM model of a single pile in saturated sandy seabed was proposed to study the reponse of pile. Meanwhile, the quasi-static method and fluid-soil coupling and contact behavior on interface was considered. Based on numerical results, responses of the pore water pressure and stress of seabed soil under wave was studied, and the deformation and internal force of the single pile were discussed. Besides, two different methods to model the pile-soil interface were discussed with a comparison of the free field seabed model and seabed model with a totally embeded pile. The results show that the pore water pressure increases significantly near the mudline and bottom of pile. Responses of pore pressure and bending moment are evidently larger in the coupling model, but the displacement response is smaller. Moreover, the totally embeded pile model is mainly affected by seabed, as the wave dominatedly acts on the model with a pile out of the seabed.
