Abstract: A newly developed three dimensional elastic visco plastic (3 D EVP) model is introduced and implemented in a FE program for consolidation analysis of soft clay under uniform load. Three key parameters, i.e., creep parameter Ψ/V , permeability k , and clay layer thickness h are varied to investigate their influence on deformation and porewater pressure of the soil. When viscous effect is taken into account, porewater pressure in the soil will be higher than that without consideration of the viscous effect. It is found that larger creep parameter Ψ/V results in higher porewater pressure and larger deformation. The lower the permeability of soil, the higher the porewater pressure, and the larger the deformation. The mechanism of viscous effect on the porewater pressure is explained.