Abstract: The dynamic interaction between the soil and the pile and the superstructure was studied by the method of integral finite element under the seismic condition. The soil side boundary is simulated by using the elastic spring-damper. Input restraint joint is used to settle continuous conditions of the different type of connective unit. Consequently, some useful conclusions are obtained by comparing the vibration of the periods and the displacement as well as the internal force of the piles under the seismic condition, with the consideration of the stiffness variations of three types of superstructures.