Research conclusions：The wind blown sand was mainly concentrated in the space of lower than 3m in Gobi area and it was up to almost 87% of total sand volume. The density of wind-driving sand increased with the increase of wind velocity at the same height. The density of wind-blown sand decreased with the raise of height at the fixed wind velocity. The analysis result of sand particle size showed in the "100 kilometers wind area", the main movement form of wind blown sand in the space of lower than 3m was in leaping movement, and the main movement form of wind blown sand in the space of higher than 3m was in suspending movement.