Discrete element method (DEM) is widely used in studies of particulate matter. Most of these studies are limited in the modeling of spherical particles due to contact algorithm. It is important for DEM to simulate non-spherical particles if wondering more authentic behaviors of granular materials. A probability-based contact algorithm is presented in this paper. Contacts between non-spherical particles are transferred into those between spherical particles with probability. The comprehensive mechanical behavior of granular material with a large number of non-spherical particles can be efficiently modeled because contact detection algorithm for spherical particles remains. To validate the presented algorithm. Hopper experiments for spherical and polyhedral particles are physically and numerically performed. To achieve higher accuracy of the angles of repose and profile of the stable particulate piles, a digital image processing method is adopted. The numerical results are in good agreement with the experimental observation, both in the spherical and polyhedral particles. The probability-based contact algorithm is valid in describing the behavior of polyhedral particles. (C) 2011 Elsevier B.V. All rights reserved.