Abstract:Vegetation species composition and species diversity in response to the distance from the plots and the center of desert were explored through the vegetation field survey in the southern edge of the Badain Jaran Desert.The results showed:(1)10 families,18 genera and 20 species were recorded in the study area.The plant type was mainly xerophyte.The type of vegetation community were shrubs and herbaceous communities.(2)With the plot extends to the outer edge of the desert,the type and number of plants increased gradually.Community structure was more complex and diversified.Shannon-Wiener index and Simpson index of plots increased while the dominance index decreased gradually.The index trend of shrub layer was consistent with the plots in α-diversity indices.However,the index change of herb layer was slight.The Bray-Curtis index of β-diversity showed a downward trend which indicated that the species substitution rate between plant community was gradually reduced.(3)Relationships between species diversity of plant and soil factors and the stepwise regression analysis indicated that the effects of soil organic matter and nitrogen content on the vegetation was significant,and there was a significant correlation between soil phosphorus in 20-40 cm and species diversity of plots and herb layer.