Geotechnical engineering problems in coastal area are often related to the behavior of the porewater. Typical examples of these problems include consolidation of soft clay and liquefaction of loose sand. In this report the dynamic response characteristics of saturated layered media influenced by drainage condition, loading rate and water depth are discussed. Saturatede ground is dealt with as a two-phase material based on the formulation of Biot. A thin layered element for describing the dynamic behavior of a fluid saturated porous layered medium is presented. The dynamic stiffness and wave propagation characteristics of the saturated two-phase grounds are given comparing with those for dry soil by using developed method.