By adding a modification to the hysteresis curves of the simple cyclic loading model proposed by the authors before, a new prediction method of the degree of damage of soil structures induced by liquefaction is developed in this paper. First of all, based on the comparison of results between the shaking table test of a dry sandy slope and its FE simulation with the proposed model, the way of modification of the model is examined. According to the examinations, the formulations of the model are modified so that the undraineds tress-strain relationships of sand observed in a laboratory test of liquefaction should be simulated precisely. Finally, the efficacy of the new formulations is verified through the results of the dynamic centrifuge model tests of an embankment on the liquefiable ground.