Abstract: Assuming the soil layers under the piles to be fictitious soil piles, the influence of sediment on the dynamic response of the piles in inhomogeneous soil is presented. Firstly, the finite soil layers under the piles are modelled as the fictitious soil piles whose cross-section area is the same as that of the piles. Using the complex stiffness transfer model of radial multi-zone plane strain, complex stiffness of different soil layers beside the piles is obtained. The complex stiffness of vertical vibration at the top of the fictitious soil piles is derived by means of the impedance function transfer method. Then, the analytical solutions of dynamic response at the pile top in frequency domain and the relevant semi-analytical solution response in time domain are obtained. The influence of sediment is investigated to obtain the nature of the dynamic response at the pile top in frequency domain and time domain. Finally, it is proved that the theoretical curves are in good agreement with those obtained from the field measurements.