Windblown sand transport is one of the most important natural erosion mechanism in arid zones. It is responsible for landform dynamics, dust aerosols emission and for damaging human infrastructure. In this thesis we present a particle-based numerical model in order to simulate the saltation phenomenon, that is the sand transport mode involving most of the transported mass under normal wind conditions. The model takes into account the fundamental physical aspects of the saltation process, which are essentially the entrainment of particles by wind, their trajectories and their impact on the ground. Starting from basic principles of single particle behaviour, the aim of the model is to obtain information on global saltation quantities, such as the sand particle concentration with respect to ground distance and the sand mass flux with respect to the wind strenght.