Abstract: Besides large compressibility, low permeability, and long deformation time, soft soil sometimes has some overconsolidation characteristics, which increases the difficulty to estimate and calculate the ground settlement. The unified hardening model (UH model) can describe many characteristics of clays well, including stress-strain relationships, stress dilatancy, strain hardening and softening, and path dependency behavior. The parameters in the model as are the same as those in the Cam-clay model. By using the the UH model, numerical simulation of triaxial tests was performed, while the FEM results and unit predicted results using UH model were compared. Threedimensional finite element analysis of deformation of an embankment on soft clay was carried out combining with an actual project. The changes in excess pore pressure, ground settlement and lateral displacement were analyzed and compared with the measured data.