This paper presents a numerical study on the earthquake analysis of a concrete gravity dam. The numerical approach is based on the multiple pre-embedded discontinuity finite element method. The equations of motion with the ground motion excitation, static self-weight, hydrostatic reservoir load and the hydrodynamic reservoir loads as the boundary conditions are solved with explicit time stepping. Mass proportional damping is used instead of the usual stiffness proportional damping since the latter drastically decreases the critical time step of explicit time integration. The Koyna dam with the genuine accelerograms recorded during the 1967 earthquake is analyzed as the numerical example. The simulation results agree with the previously reported results by other studies, i.e. similar crack propagation in the monolith is predicted here.