Ridge-tillage is an effective farming practice for soil and water conservation, extensively used in rainfed cropland in semi arid regions, however, its mechanism of controlling wind erosion is unclear and calls for further research.In the experiment field with ridges 25 cm high and 1 5 m in between, synchronous observation was made of wind profiles from 0 m to 4 m at windward, bed between ridges and leeward.Aerodynamic parameters of these sites, including hourly average wind velocity, aerodynamic roughness, friction velocity, and absolute and relative fluctuation intensity of wind velocity, were analyzed.Results indicate that hourly average velocities of the layer of 0~1 m at the site in between ridges and the leeward site were obviously lower than at the windward site, and the biggest drop was observed at the height of 0.3 m.Horizontally, the parameters, such as extent of the decrease in wind velocity, aerodynamic roughness and friction velocity, were all decreased with the distance of the observation point from the ridge.And all the three parameters were the biggest at the site between ridges whereas the smallest at the windward site, 1.5 m from the ridge.Increasing with wind velocity, absolute fluctuation intensity was a logarithm function of the height in the vertical direction whereas relative fluctuation intensity of wind velocity decreased with height in the 0~1 m layer of the profile, and changed little in the layers above 1 m, but increased with the decrease in distance of the observation site leeward from the ridge at the height of 0.05 m.It is the highest at the site between the ridges, bringing the shear stress of airflow on soil surface up to the peak, which is obviously unfavorable to wind erosion control.