The topsoil samples of 0 – 2 cm were collected from farming land, fenced grassland, grazing grassland and tourist area in Xilamuren desert steppe and used to investigate soil particle size characteristics. First，the soil particle size distributions were identified by laser diffraction technique. Second, the particle size parameters of average particle size, standard deviation, skewness, kurtosis, and fractal dimension were subsequently calculated. And then, the erosion particle range was discussed. The results indicated that: 1) the topsoil particles in desert steppe were mainly composed of sand and silt, while the clay content was extremely low. Soil particle size followed the order: farming land < fenced grassland < grazing grassland < tourist area. Soil particle size distributions were all in poor sorting. The kurtosis was medium, wide flat, wide flat and medium for farming land, fenced grassland, grazing grassland and tourist area, respectively. The fractal dimensions were 2.39, 2.26, 2.20 and 1.88 for these land using types. Correspondingly, the skewness of these land using types was negative, nearly symmetrical, positive skewness and partial positive, respectively. The skewness can be used as an effective particle size parameter. 2) Based on the analyses of frequency curves of soil particle size and the average distance, it was found that when soil particles were about 134 μm and 454 μm, which are the easiest to be erode by wind under near nature conditions. The particle size parameters and fractal dimension showed that the grazing and tourism accelerated wind erosion of topsoil in this region. Soil particle distribution was becoming wide, and soil coarse particles increased gradually.