Abstract:The shrub community is the most important ecosystem components in Ulanbuh desert.The community structure and quantitative characteristics of shrub community was researched,which can provide the theory basis and the practice foundation for protecting biodiversity and sustainable utilization of plant resources in the area.According to the quadrat investigation material,the community structure and quantitative characteristics of typical shrub community was analyzed by the species composition,life form spectrum,coverage characteristics,species diversity and similarity of community.The results showed that:(1)The main community type was the community of Haloxylon ammodendron,Nitraria tangutorum,Ammopiptanthus mongolicus,Artemisia desertorum,Artemisia ordosica and Kalidium foliatum.The plants belong to 58 species,47 genera,and 12 families.Most of plants belong to chenopodiaceae,asteraceae,gramineae and leguminosae,which were the characteristic families in arid desert region.(2)The annual plant made the biggest percentage in the community of H.ammodendron,N.tangutorum,A.mongolicus and A.ordosica,which were widely distributed in Ulanbuh desert,so it showed the arid climate in study area.(3)The proportion of shrub plant coverage were more than 50%,so the contribution rate of shrub plant for community coverage was greater than herbs.(4)The communities which were distributed in the better habitat conditions had high biodiversity.The H′ diversity index varied between 0.98~3.42.The D diversity index varied between 0.415 5~0.879 5,the species composition of each shrub community was relatively simple.(5)The similitude coefficient of each community varied between 0.068 2~0.604 7,so each community’s similarity did not reached the level of very similar.There was mild similar among the three community,which were N.tangutorum,H.ammodendron and A.mongolicus,but the similitude coefficient between the other communities were less than 0.25.It showed there were great difference between community habitats.