Based on quantitative analysis of soil texture using soil fractal dimension of particle size distribution, the distribution of soil fractal dimension is a significant negative correlation with sand content（>0.1mm）, and positive correlation with proportion content of silt and clay（<0.05mm）（p<0.0001）. Increasing in sand content can result in decreasing of fractal dimension, and increasing in silt and clay can result in increasing of fractal dimension. However, the variation tendencies in soil fractal dimensions are different because of sand content or silt and clay content changes, while there is a same range on variation of fractal dimension. The fractal dimensions will be decreased or increased by 0.022 when increasing in 1% of sand content or silt and clay. So, soil fractal dimension can be considered to be one of quantitative indices for evaluating desertification. In comparison with soil layer of depth 50～70cm, the texture of surface soil (0～5cm) appears coarser. This characteristic of soil texture distribution in soil profile benefits to rainfall infiltration in deep soil and ensures available moisture for deep-rooted Ammopiptanhus mongolicus and accompanying shrub species. The soil texture distribution in profile partly supported conceptual model by some researchers described, and tested the hypothesis that the coarse-texture soil supports the dominance of shrub species in comparison with herbaceous species. However, spatial heterogeneity analyzed showed that spatial heterogeneous scale of soil particle content beyond the confine of canopy and inter-space of shrubs due to strong wind erosion occurred on soil surface, and the morphological differences in ramification and height of plants result from developing degree of sand mound by shrubs in the psammo-vegetation. Furthermore, our results do not supported the hypothesis on ‘fertile island ’of shrub since shrub roles for fertile island formation were weakened by frequent wind erosion in desert ecosystem. This soil habitat of Ammopiptanhus mongolicus community prevent other both woody species and herbaceous from invasion and plays a significant role in maintain community stability. These results can be contributed to knowledge to understand the conversation mechanism of unique Tethys sea relic floristic species.