Abstract:The wind erosion of farmland in the agro-pastoral acetone of northern China is very serious, which causes degradation of soil resources. Taking Bashang district as a typical area of agro-pastoral acetone, by field sampling and comparing the differences in soil properties between farmland and nearby natural grassland, the loss characteristics of fine particles in farmland soils led by wind erosion as well as its impact on soil physical and chemical properties were studied in the paper. The results showed that, compared with natural grasslands with weak wind erosion, the contents of clay and silt in farmlands decreased by 30% and 14%, respectively. The grain sizes of lost soil concentrated in 0~40 μm, of which the loss of fine particles with sizes of 1.8~24.0 μm was the largest. The loss of fine particles in farmland soils resulted in the increase of sand and gravel in farmland soils by 7% and 75%, respectively, also the averaged particle size of soil increased 16%. Those indicate that the farmland soils have serious tendency of coarsening and desertification under the long-time effect of wind erosion. With the loss of fertile fine particles, the soils of farmland became barren. The results showed that the contents of carbon (C) and total nitrogen (N) in farmland soils decreased significantly, with a declining range of about 29% and 24%, respectively. The ratio of C to N (C/N) also declined obviously and the content of soil fertility reduced. However, the loss of fine particles had no significant influence on the proportion of erodible particles in soil. The change of soil erodibility by wind was not obvious in farmland soils.