Stress of diaphragm wall is analyzed by plane finite element method for high earth-rockfill dams built on deep soil foundation. The differences of stress are studied with two kinds of different constitutive models, i.e. elastic model and nonlinear elastic model, and meanwhile, the influences of the height of dam and diaphragm wall for this two constitutive models are also compared. The results show that, the variation laws of the stress of diaphragm wall are similar for both of the models. But, the stress computed by nonlinear elastic model is much smaller than elastic model does. Under the condition of low stress, the results are similar for the two models, but have big differences for high stress. In addition, for this two models, with the increasing of height of dam and diaphragm wall, the maximal values of the stress are increasing constantly, and relative error of the maximal value of the stress as well, which have the linear relation with the height of dam and diaphragm wall. So, for the conditions of high dams or deep soil foundations, nonlinear elastic model is the right one to use because of the high stress of diaphragm wall.