Abstract: Dynamic fracture analysis of gravity dam is carried out by the scaled boundary finite element method (SBFEM). The effectiveness of the proposed approach for the evaluation of dynamic stress intensity factors is validated by the numerical benchmark examples. The influence of the unbounded foundation is modeled by a high-order transmitting boundary based on the continued-fraction solution of the dynamic-stiffness matrix, which is characterized by its good convergence and high degree of accuracy. Finally, the earthquake response of the gravity dam-reservoir-foundation is analyzed and the time history of the dynamic stress intensity factors (DSIFs) is provided. The results are compared with those of the mass-less base model and those for the case of intact dam. It is demonstrated that the dynamic stress modeled by mass-less foundation overestimates the earthquake response of the dam by 20%―25%.