Abstract: Generally the toe of the bank slope in front of the pile-supported pier has to be dredged to meet the requirement of the water depth for the berth of ships, and the top of the slope behind the pier must be backfilled and elevated to make connections with the land carriage. Then the natural state of equilibrium of the slope is destroyed, and some deformation and displacement are inevitably induced in the soil mass which will exert an undesirable influence on the pile foundation. This is a typical problem of the interaction between the so-called "passive pile" and soil mass, and has been scarcely studied in the literatures of geotechnical engineering. Field observation, model tests and numerical analysis in studying the interaction between pile-supported pier and bank slope are briefly described with some preliminary results presented.