[Objective] The objective of this study is to provide the foundation for selecting the excellent afforestation species in sandy area by establishing the drought resistance evaluation system.[Methods] Two-year-old seedlings of the twelve desert shrubs in Ulan Buh desert ecosystem were selected as the experimental materials. Through measuring seven water physiological indexes

the drought resistances of the twelve desert shrub species were studied by the principal component analysis and cluster analysis.[Results] (1) The water potential of Ephedra distachya

Nitraia tangutorum and Caragana korshinskii was lower than the other nine shrub species. The bound water content and the ratio value of bound water and free water(Va/Vs) of Zygophyllum xanthoxylon was relatively higher

which was 64.20% and 3.3

respectively. The transpiration rate of Atraphaxis bracteata

Nitraia tangutorum and Tamarix chinensis was significantly lower than the other nine shrub species. The constant weight time of Haloxylon ammodendron and Ephedra distachya was the longest

and it was 144 h. The residual moisture content of Ammopiptanthus mongolicus was the highest(44.80%).(2) The drought resistance of the twelve desert shrubs in Ulan Buh desert ecosystem was significantly influenced by water potential

Va/Vs

residual moisture content

bound water

transpiration rate and constant weight time

and the cumulative variance contribution rate reached to 87.59%.[Conclosion] According to the drought resistance

twelve desert shrubs can be clustered into 3 categories. Ephedra distachya belongs to the strong drought-tolerant shrub; Haloxylon ammodendron

Nitraia tangutorum and Zygophyllum xanthoxylon belong to the medium drought-tolerant shrub; Hedysannn scoparium

Hedysarum mongolicum

Tamarix elongate

Caragana korshinskii

Ammopiptanthus mongolicus

Atraphaxis bracteata

Calligonum mongolicum and Caragana microphylla belongs to the weak drought-tolerant shrub.