Abstract: The reliability-based design (RBD) is one of the most crucial measures to study and guarantee geotechnical engineering safety. Through quantitative analysis of uncertainty in earth-rockfill dam engineering, the failure probability can be evaluated and may provide a reference basis for the seismic performance design and safety risk assessment. By selecting the crest seismic settlement ratio as the seismic safety index, the seismic reliability analysis of high earth-rockfill dams, which incorporates the uncertainty of earthquakes and dam material parameters, is proposed. First, based on the seismic intensity probability model, the seismic acceleration corresponding to the earthquake intensity occurrence probability is used as the earthquake intensity factor. The artificially generated seismic waves are adjusted for finite element calculations. Then, the Gaussian process regression (GPR) model, which is capable of solving the highly nonlinear regression problem with small samples, is used to establish the nonlinear mapping relation between material parameters and crest settlement ratio. The Monte-Carlo simulation method is employed to calculate seismic failure probability. For verification, the proposed method is employed to calculate the seismic failure probability of Zipingpu concrete face rockfill dam.