Abstract: In view of the complex nonlinearity of soil medium, particularly considering the great influence of strength degradation of saturated foundation soil under earthquake incident, the study of cyclic loading response and the mechanics of cyclic liquefaction of soil has been known as one of the most important issues in the seismic research and design of civil engineering structures. Considering that normally consolidated soil turns into overconsolidated state once experiencing stress unloading in cyclic loading, which has great influence on the mechanical properties of soil in turn, and in order to investigate the effect of overconsolidation factor and the corresponding evolution of over-consolidation ratio (OCR) under cyclic loading, comparative numerical simulation studies are carried out through both drained and undrained triaxial compression tests based on the subloading surface Cam-clay model. The stress-strain relationship, compressibility and the development of excess pore water pressure are studied in detail. The comparative test results show that with the consideration of overconsolidation factor into the classical Cam-clay model, the yield strength, as well as the corresponding liquefaction resistance of soil, is improved significantly. Based on the comparative study of overconsolidated soil's mechanical properties and liquefaction resistance, a dynamic nonlinear FEM model of pile-soil coupled system with saturated soil foundation is established based on the program of ADINA81 along with the development of constitutive module of the subloading surface Cam-clay model, and the comparative study of the seismic response of pile structure is carried out with different constitutive models. Simulation results show that the seismic response derived from the subloading surface Cam-clay model lies between classical Cam-clay model and linear elastic model. Through the comparison, it can be concluded that by taking the influence of overconsolidation factor into consideration, the foundation soil demonstrates better liquefaction resistance and bearing capacity, and thereby affects the corresponding seismic response and force conditions of the structure.