Abstract: The engineering background and guiding principals ofseismic safety evaluation of concrete large dams in China are presented inthis paper. Particularly, the special features and the linear and non-linearanalytical methods for seismic responses of high arch dam system aredescribed. The methods of the random seismic response and reliabilityassessment of concrete large dams are also discussed. Finally, based on theresults of dynamic tests of dam concrete with specimen of fully-gradedaggregates, the study on the dynamic failure process and mechanism of damconcrete using three-dimensional meso-mechanics analysis checked bycomputerized X-ray topography technique is briefly reported.