A case study on the quantity of aeolian sand erosion and deposition of fences with different height was carried out in the observation station of Chinese Academy of Sciences at southeast of Tengger Desert.The fences with different heights were deployed in the field.Combining the observed weather data and the data of aeolian sand erosion and deposition of barrier-free flat desert over the same period,it is concluded that the sand prevention effect of the fences with the height between 50 and 90 cm is better than others.And the fences with the height between 60 and 70 cm have the best effect.However,the quantity of sand deposition is different in the up and down wind.The quantity of sand deposition is with the fences of 70 cm in the upward wind while there was more sand with the fence of 60 cm in the downward wind.In the upward wind,sand is accumulated.In the downward wind,the intensity of aeolian sand erosion and deposition change with the height of fences.In practice,we must consider the properties of protection object.Only in this way can we achieve better sand protection effect.Besides,according to the pattern of cross section,the quantity and the intense of aeolian sand erosion and deposition,the sector of the front and rear of fences was divided into sand accumulation area,wind erosion area and balance area