Abstract: By means of the finite element software named ABAQUS, the settlement and deformation of the pile-soil system under vertical load are analyzed. The foundations with pile groups can be divided into three categories: different pile spacings, different pile lengths, and different pile numbers. For numberical analysis, the Mohr-Coulomb criterion is adopted. Based on some large scale mode tests on pile groups, it is found that the results of 3D FEM analysis using ABAQUS software are convincing. The results show that the settlement of pile group foundation decreases if the pile spacing or length increases. Compared with the settlement and deformation of pile group foundation with different pile numbers, the settlement increases with the number of piles, nevertheless, the settlement value is stable when piles are larger than number 25×25. In other words, the change of the settlement of the pile foundation is not obvious with the increase of the pile number if it exceeds a certain level. Many researches should be done to show whether or not the foundation settlement of smaller number (25×25) of piles can be calculated, and the settlement of the foundation with larger number of piles meets the need of engineering design.