In this thesis, two-dimensional floating pier consists of single rectangular impermeable pontoon and rigid beam is studied. The purpose of this study is to present a theoretical solution for linearlized problem of incident waves acting on a floating pier with pile-restrained. All boundary conditions are linearlized in the problem which is separated into a scattering problem and radiation problem with unit motion amplitude. The method of separation of variables is used to solve for velocity potentials. For the radiation problem with unit heave and rotate amplitude, the boundary value problem with nonhomogeneous boundary condition beneath the structure is solved by using a solution procedure proposed by Lee(1995). By calculating wave force from velocity potential, and equations of motion of the floating structure, an analytic solution for the problem is developed. At last, using finite element method to calculate the dynamic analysis on the pile acting by the pontoon and incident waves.