Abstract: The motion of particles on surface is made up of three fashions: creep, saltation and suspension. Saltation is most important among the three movement fashions not only because of the fact that saltation particles account for 75 percent of total transported sand mass bu t also that it is chiefly responsible for sand drift disaster. Meanwhile, the Physics of Blown Sand that takes saltation mechanism as the main research subject is not well established because of the limitations of researcher's knowledge and objective conditions such as backward experimental conditions and modeling techniques. Thus the theory of wind sand current can't been developed smoothly. Accordingly, the theory on wind sand can't been applied to practice effectively. Research on wind sand current is made up of macroscopic and microscopic studies. Macroscopic study aims at drifting sand flux structure and dynamic process, while microscopic study lays particular emphasis on the motion state of a single sand particle. Macroscopic study in connection with microscopic study is reasonable to solve a series of problems which exist in the Physics of Blown Sand. However, macroscopic study has been seriously divorced from microscopic study for a long time because of the immaturity and lack in realizing the importance of motion mechanism and parameter distribution of the lift off particles. In view of the facts above, the paper summarizes the research history and advances at ho me and abroad in the above mentioned aspects, and points out three present problems which are urgently necessary to solve: (1) The research on impact mechanism of particles needs strengthening so that perfect impact model is to be established gradually. (2) Macroscopic study should be connected with microscopic study through the distribution function in motion state of lift off sand particles. (3) Saltation model of particles needs to be perfected further.

Key words: The Physics of Blown Sand, The saltation of sand particles, The distribution functions of motion state