Using FEM for geotechnical design of constructions with high impact of the soil – structure interaction is a common practice. However, for obtaining results close to the real behavior of the analyzed structures it is required to use complex constitutive models for all materials, especially for describing the soil behavior. Paper presents the differences in the numerical modeling when three different constitutive laws are used: one linear elastic – perfectly plastic and two nonlinear elastic - hardening plastic laws. Comparisons between numerical modeling and laboratory tests are presented in order to emphasize the differences between the constitutive laws and to calibrate their parameters. As well, a numerical calculation using FEM for an embedded retaining wall is presented, using different soil constitutive models. The results regarding the displacements of the wall and the bending moments in the wall are compared with the experimental values.