This article presents the results of numerical simulations of cyclic loading tests conducted on particles that simulate railroad ballast. The objective of this study was to evaluate the deformation of ballast under a large number of loading cycles and to study the influence of the two different particle size distributions. One of them was according to particle size distribution recommended by Indraratna and co-workers in the past as an improvement to Australian Standard and the other was prepared in accordance with Brazilian standard. The discrete element method offers a new means of studying the response characteristics of railway ballast. The basic idea of discrete element method (DEM) is that arbitrary discontinuities are divided into a set of rigid elements, making each rigid element satisfy the equations of motion, use time step iteration method for solving the equations of motion of rigid elements, and then obtain the overall movement patterns of arbitrary discontinuities. In this study, the discrete element method of analysis has been used to simulate the geotechnical behaviour of railway ballast observed during the testing.