Wind erosion is a significant factor limiting agricultural development in the north ecotone between agriculture and pasture. In order to study the mechanisms of windbreak,sand-fixation and protection benefits in shelter belts,wind erosion under three types of protective forest model was simulated in a wind tunnel experiment using the PIV system.Threshold shear velocity and wind erosion rate were measured,and velocity characteristics were obtained by using InsightNT softw are. Results show that the combination between arbor and shrub is a best protective forest structure model.The reason is that the structure model can significantly reduce wind velocity on soil surface.