A hybrid Open-MP (Shared memory) - MPI (Distributed memory) parallel Computational Fluid Dynamics (Li-D)Discrete Element Method (DEM) model has been developed for simulating fluidization of cylindrical particles in a fluidized bed. In the DEM model, five, seven, nineteen and sixty overlapping spherical particles in different formation methods including single-row, multi-row and hybrid formations have been used to represent one cylindrical particle. The simulation results of the hybrid representation for mimicking a cylindrical particle are more accurate than other representations: particularly in terms of, particle number density along the bed height and particle orientation distribution in the bed, in comparison with previously reported experimental data. The simulation results show that the preferential orientation of the partides is horizontal in the fluidize bed, but the number of particles with vertical orientation increases when they approach to walls. Only multi-row and hybrid formations could capture this increase near the walls. (C) 2019 Elsevier B.V. All rights reserved.