A DEM study of a rocking particle bed is performed to show the effects of rocking frequency and amplitude on particle discharge. Six rocking frequencies of f(r) = 0, 0.1, 0.2, 0.3, 0.4, 0.5 Hz with seven rocking amplitudes of theta(r) = 5 degrees, 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees are simulated respectively. The particle distributions, discharged fractions, flow rates, particle trajectories and kinetic energies are compared and analyzed in detail to show and explain the features of particle discharging process under different rocking conditions. The rocking frequency is found to be the primary factor to determine the direction of influence on particle discharge, i.e. either beneficial or detrimental, whereas the rocking amplitude is the secondary factor to magnify the primary influence on particle discharge. In addition, the flare angle of the bed can determine the mode of influence on particle discharge, i.e. either a linearly varied discharge or an oscillated variation of discharge. The results are helpful to improve the process control and optimal design of the particle discharge beds in many engineering applications. (C) 2016 Elsevier B.V. All rights reserved.