Abstract: An effective method was proposed to predict the ground responses in the near field due to traffic on a highway viaduct.The basic assumption was that a pier of the viaduct was supposed to move as a rigid body,so that the motion at the footing center could be derived from the measured data at the pier.A pseudo-3-dimmentional FEM procedure was utilized to derive the impedance function at the footing center and the transfer functions at specified points in the near field.Further more,the ground responses were predicted and validated by the measured records.Good consistency was achieved for the cases of a test-run truck as well as ordinary traffic.Therefore,the present method was reliable and could be widely applied for viaduct traffic.