In order to study the effect of the water infiltration due to the rise of the water level of the rivers on the river dikes, a series of two-dimensional numerical analyses of experiments are carried out using a multi-phase seepage-deformation coupled method for unsaturated soil. The mechanism of the surface deformation and the strain localization on these soil structures are discussed mainly with respect to the water permeability of the soils. Results obtained by the simulations show that the deformation of the embankments significantly depends on the water permeability of the soil and it is localized on the slope surface at the river sides. The larger the saturated water permeability of the soil, the velocity of the seepage flow and the deformation on the surface of the river embankments are larger. The method adopted here, can effectively be used to study the practical seepage deformation coupled problems on unsaturated soils.