Abstract:Tianshan Mountain is distribution center of Arabidopsis thaliana and its closely related species in the world. The resource advantage of this region is obvious. In shallow zone of northern Tianshan Mountain, a typical sample plot of 50m 50m were selected to analyze the species construction and soil physicochemical properties. Ripley′s K (d) function was used to determine the sptial pattern of A. thaliana and relationships between A. thaliana and its adjacent species. 7 families and 23 species were observed in the sample plot and 70% were ephemeral plants. Seriphidium kaschgaricum was the constructive species. A. thaliana in this plot mainly took on aggregated distribution in northern slope, and had a higher L(d) value than other species within 3m scale. The sptial distribution of A. thaliana was positively correlated with middle size S. kaschgaricum under a range of 5m, while negatively correlated with Malcolmia africana, Salsola brachiata, Suaeda dendroides and Ceratocarpus arenarius under a certain scale. The distribution of A. thaliana depended on shading, humidity and abundant soil organic matter condition created by S. kaschgaricum. Niche of A. thaliana differed largely with chenopodiaceae. A. thaliana required a more specific habitat than A. pumila, M. Africana, Alyssum desertorum, Tetracme quadricornis, Leptaleum filifolium and Lappula semiglabra, which was a kind of ephemeral plant. In the dry stress condition, intensity of environmental selection was higher than interaction between intraspecies. Density-dependence dispersal was weak. The dispersal strategy of A. thaliana was to produce more seeds, generate fruits that were hard to crack to keep seeds disperse in a short distance, and make full use of the maternal habitat to propagate.