Abstract: Seismic fragility analysis is one of the three issues (seismic hazard analysis, seismic fragility analysis and seismic loss assessment) in seismic risk analysis. It describes the probabilities of structural damage caused by earthquakes with different probabilities of exceedance. In the paper, non-linear finite element analysis is performed to structural samples whose mechanical variables are sampled by Latin hypercube sampling technique. Based on seismic damage index of dam-foundation system, fragility curves of dam monolith and slippage at the interface between dam and foundation are obtained, as well as the fragilities of the entire dam-foundation system. The above analysis is helpful to seismic design, retrofit and upgrading of dam-foundation systems.