Abstract: By using interspecific association determination methods, this paper analyzed the characteristics of interspecific associations among the 24 main plant populations in the communities with Arabidopsis thaliana occurrence in middlepart of northern Tianshan Mountains. The variance ratio (VR) of the overall associations among the 24 populations was 1.55, showing a significant positive association. Among the 276 species pairs of the populations, there were 123 pairs showing positive correlation, 150 pairs  negative correlation, and 3 pairs with no correlation. The χ₂ test indicated that there were 61 species pairs showing significant or very significant positive correlation, and 24 speciespairs showing significant or very significant negative correlation. 232 species pairs had the Ochiai values>0 and<0.6, 12 species pairs had the Ochiai values>0.6, and 32 species pairs had their Ochiai values=0, suggesting that most
 of the species pairs had weak or no interspecific association. The detrended correspondence analysis (DCA) indicated that the distances between species on the ordination diagram better reflected the strength of interspecific association. A. thaliana had close relations with and high dependency on droughtresistant species Seriphidium kaschgaricum and Salsola collina, indicating its stronger droughtresistance, and had significant positive associations with its a
djacent species Alyssum desertorum, and with Leptaleum filifolium and Tauscheria lasiocarpa, indicating that these species had similar ecological requirements and habitats. However, the association between A. thaliana and A. pumila was weak, showing a divergence of their habitats. Most of ephemeral cruciferous species had stronger associations among them and with the dominant species in the communities, reflecting the distribution characters of cruciferous species in arid area.