The structure of bed-load layer is characterized by:(i) irregular motion of the individual saltating particle;(ii) particle/flow interaction; and (iii) particle/particle interaction. In this study, the motion of saltating particle is described by the irregular successive saltation model, and the PSI (Particle-Source-In) Cell model is employed to couple the successive saltation model with the k-ε model of turbulence for describing the continuum flow field. Furthermore, PSI-Cell model is modified by considering the effect of the interparticle collision. Results of the present simulation agree well with the experimentalresults on the existing probability density and the velocity profile of saltating particle.