Abstract: The damage mechanisms of concrete materials and structures were analyzed by the discrete element method (DEM). On mesoscopic level, a concrete material numerical model was developed based on the DEM considering the composition of concrete materials which were coarse aggregates, mortar and their interface. On macroscopic level, a concrete structural numerical model was proposed assuming that the concrete was homogeneous. The simulation results indicated that the failure processes of concrete materials under uniaxial loading conditions could be well predicted by using the two-dimensional mesoscopic numerical model, but the damage processes of concrete materials under combined loading conditions could not be calculated correctly. The failure processes of reinforced concrete members could be accurately simulated by the DEM-based model on macroscopic level, but the calculated results had a great dependency on the shape of the elements. The collapse processes of reinforced concrete structures could also be predicted well by using the macroscopic numerical model, but the computational efficiency of the model should be further improved.