Dynamic behavior of a caisson type quay wall resting on pile foundation with exp anded base was numerically evaluated by a liquefaction analysis based on effective stress model during 1995 Hyogo-ken Nanbu Earthquake. The effective stress model used for the liquef action analysis during earthquake motion was a strain space multiple mechanism model. The deformation during the earthquake ground motion induced due to pore water press ure in the soil behind the caisson quay wall. Though the displacement response of the caisson q uay wall with pile foundation was smaller than that of the caisson without pile foundation, the deformation was mainly induced by the increase of pore water pressure.