Particle damping is a technique of providing damping with granular particles embedded within small holes in a vibrating structure. Particle-to-wall and particle-to-particle collisions arise under the vibrating motion of the structure. As a result, the structure and the particles will exchange momentum and thus dissipate kinetic energy due to frictional and in-elastic losses. The particle damping technology has been used successfully in many fields for vibration reduction. However, it is difficult to predict the damping characteristics due to complex collisions in the dense particle flow. In this paper, we utilize the discrete element method (DEM) for computer simulation of particle damping. By considering thousands of particles as Hertz balls, the discrete element model can describe the motions of these multi-bodies and determine the energy dissipation. We describe a DEM modeling system with an efficient collision detection algorithm for large-scale particle problems. The simulation system is validated by comparing with experimental results of a physical system. The DEM simulation system is further examined with examples for its computational complexity and effectiveness for different density parameters. It is concluded that the particle damping is a mix of two damping mechanisms of impact and friction. It is further shown that the relative significance of these damping mechanisms depends on a particular arrangement of the damper. (C) 2004 Elsevier B.V. All rights reserved.