Abstract: Numerical prediction on seismic response of liquefiable soil-structure system is susceptible to varying model input parameters. In order to detect soil parameters that have most significant effects on the seismic response of pile-soil-bridge structure system in liquefiable ground, this paper firstly calibrated the numerical approach by simulating a centrifuge testing. A typical model of pile supported bridge structure embedded into an inclined ground with three layers (overburden clay crust, saturated loose sand and dense sand, respectively) was then established. Sensitivity analysis focused on soil physical properties as well as structural properties. The parameters were the displacement and acceleration of the ground surface, and the displacement of the superstructure. Linear to low-level nonlinear trends between most of the soil parameters and the demands were obtained. The first-order sensitivity analysis indicated that, among the input parameters, the friction angle of loose saturated sand, the ground inclined angle, and PGA has the most significant effect on seismic response of the ground and structure. Sensitivity analysis also revealed the soil parameters with low-level uncertainty. In general, the results of this paper are beneficial supplements for accurately evaluating the seismic response of bridge structures in liquefied and lateral spreading ground as well as the optimal design of the corresponding shaking table tests or centrifuge tests.