Abstract:Caragana liouana, C. microphylla and C. korshinskii are three of the most common species which are widely planted in an agropastoral transition zone in the arid and semiarid area of northern China. However, the ecology effect of these types of vegetation planting on soil properties and bacterial communities in salinealkali soil has received far less attention. The root with any adherent soil particles and bulk soils from replicated plots representing three different species of Caragana were collected at a research site in Ningxia, China. The rhizosphere soil was washed from the roots, and community diversity and structure of rhizosphere and bulk soil bacterial were analyzed by using barcoded pyrosequencing of the 16S rRNA gene amplicons. Our results showed that: (1) soil pH and EC were decreased significantly in bulk soils of the three Caragana species when compared with control soil, while the opposite patterns were found in total P and N. (2) Across all samples, Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Gemmatimonadetes, Planctomycetes, Chloroflexi, Acidobacteria and Euryarchaeota were the most dominant bacterial phyla which represent 81.7%-97.5% of all taxon tags. Shannon index indicated that the αdiversity of the soil bacterial community did not affected by short term of Caragana plantation. (3) A principal coordinates analysis found that the bacterial community structure in rhizosphere of C. microphylla obviously distinct from that of C. liouana and C. korshinskii. Meanwhile, the same pattern was detected in the bacterial community of bulk soil under C. microphylla. At the genus level, the relative abundance of 12 dominant bacterial genera, such as Alysiosphaera, Entotheonella, Haliangium, Mesorhizobium, Ensifer, Pseudoxanthomonas, Rhizobium, Phyllobacterium, Phenylobacterium, Novosphingobium, Luteimonas, Brevundimonas and Chitinophaga, were significantly accumulated in the bulk soil of C. microphylla. (4) Distance based redundancy analysis indicated that soil EC, total P and N exerted strong influences on the structure of the bulk soil bacterial community and explained 23.5%, 25.4% and 22.2% of community variances between samples, respectively. Our results suggest that shortterm plantation of Caragana did not affect the α diversity of bulk soil bacterial community and different species of Caragana exerted distinct effects on the structure of the bulk and rhizosphere bacterial community.