Abstract: A 3D elastic-plastic dynamic analysis procedure platform for concrete faced rockfill dams (CFRD) is developed by combining the elastic-plastic model for rock-fill materials with the plastic damage model for concrete. The damage occurrence and development process of concrete slabs under earthquake load are investigated using the procedure. The results show that the maximum slope-direction tensile stress of the slabs occurs at the height of 0.65 of the dam and results in the tensile damage of the slabs at this position during earthquakes. Also, the tensile damage of the slabs occurs at the height of 0.85 of the dam because of the “whiplash effect”. The plastic damage model for concrete can reflect the damage process of the slab precisely. The damage variable can be used to analyze of the damage distribution and weakness position of the slabs. The research results may provide an effective method for the studies on the limit aseismic capacity and the aseismic design of CFRDs.