Abstract: On basis of nonlinear continuous mechanics, the rate of Jaumann stress and the theory of Biot consolidation for saturated soil, the settlements and pore water pressure of a ground are calculated and compared by large strain method using Total and Updated Lagrangian formulation and small strain method. The results show that the deformation and pore water pressure are same for the three methods at small strain, but very different at large strain. So the comparison of large strain method and small strain method should be carried out with total stress method. The paper also points out that the final settlements of large strain method are smaller than that of small strain method, and they are seriously affected by the length of time step.