Abstract: Rockfill material is featured with dilatation, shrinkage and creep; and its creep can seriously affect stress and deformation in the core wall and concrete face slabs of a high dam. By conducting creep tests on different rockfill materials, we have developed a double-yield surface creep model that can simulate visco-elasto-plastic behaviors of rockfill. This model was applied to analysis of the stress in the concrete face slabs of the Shuibuya concrete faced dam and its settlement deformation. The calculations show that the model can well describe the behaviors of dilatation, shrinkage and creep of different rockfill materials under all kinds of loading conditions tested in this study. The creep of rockfill causes an increase in dam deformation and a stress growth in concrete face slabs, with the greatest effect on the slab’s axial tensile stress of an increase up to 30%, and the second greatest on its stress along the slab slope. The creep effect on a high dam above 200 m has not yet completely decayed even after five years of full storage operation. Analysis of our field observation data reveals that the wetting-drying cycle of exposure to sun and rain could lead to longtime deformation of rockfill materials. This factor is neglected in our creep model, and therefore the simulated creep effects are smaller than the measurements.