Abstract: We present a numerical investigation on the two-dimensional liquid-particle two-phase flows passing a circular cylinder at high Reynolds number.Here we apply the discrete vortex method(DVM)to compute the unsteady and unstable water flows,and adopt a Lagrangian approach to simulate the particle motion in flows.We numericaly demonstrate that the definite interrelated structure exists in the particle motion and the vortices in liquid-particle two-phase flows:the motion of intermediate size particles is obviously influenced by the vortices.When water passes a circular cylinder at high Reynolds number,the unstable flow with massive separation is formed,the complicated motion of vortices exists in the wake region.The intermediate size particles are separated from the liquid-particle mixture,then move toward the wake vortex region, finally accumulate in the vortex structures.