Discontinuous deformation analysis (DDA) proposed by Shi (1988) is a discontinuum-based method for simulating the discontinuous deformation behavior of a jointed rock mass. DDA adopts the implicit algorithm and establishes the simultaneous equilibrium equations by minimizing the total potential energy of the entire block system. Stepwise approach is used to accumulate small displacements and deformations of the blocks to large ones. The contacts are treated by using the penalty method. Because DDA keeps the advantageous features of both FEM and explicit DEM, it has been considered one of the more promising discontinuum methods in rock mechanics and has been widely applied in rock engineering analysis. This paper investigates the potential application areas of DDA method. The original DDA algorithm has been modified and applied to simulate shock wave propagation and rock failure process. The results of numerical examples show fair agreement with field or indoor test data, indicating that the modified DDA method has a powerful capability in solving many difficult rock mechanics problems.