Achnatherum inebrians (Hance) Keng, which is belonged to genus Achnatherum Beauv, Gramineae family, also known as Oxytropis glabra, is one of poisonous perennial herbs on grassland and is wildly distributed in Inner Mongolia, Ningxia, Gansu, Qinghai and Xinjiang province of northwest China. It is toxic to hoofed mammals of the genus Equus, however, they are hardy and easy to grow in arid and semi-arid areas and played active role in improving ecological environment. The toxic ingredients extracted from the plant are usually used as anti-cancer drugs, immune modulators; such as Swainsonine, one of well studied anti-cancer drugs that often used to stimulate bone marrow cell proliferates. Therefore, the plant is worth of fullly usage and utilizing it rationally. In this study, a culture-independent of analysis were chosen to investigate the endophytic bacterial composition and diversity associated in Achnatherum inebrians. Total community DNA were extracted by modified CTAB-SDS DNA extraction protocol from plant stem, leaf and root which were grinded up using liquid nitrogen grinding method after strictly surface-sterilization. To construct 16S rDNA clone libraries, endophytic bacterial specific primer pair 799F and 1492R were selected to amplify bacterial 16S rDNA partial gene, and then PCR products were ligated into a PMD18-T Vector and transformed into Escherichia coli DH 5α. Transformants were selected by blue and white selection. Positive clones were analyzed by Restriction Fragment length polymorphism (RFLP), and clones with unique RFLP patterns were selected for sequencing, alignment and constructing 16S rRNA gene phylogenetic tree. In total 249 clones were screened, which could be grouped into 57 operational taxonomic units (OTUs), based on Hae III digestion. These were divided into four phyla (Proteobacteria, Firmicutes, Actinobacteria, Bacteroides) and one unknown group by phylogenetic analysis. Of them, 74% of clones classified into 37 genera of bacteria phylum were highly related to cultivable species with high 16S rRNA gene similarity (>96% sequence similarity); and among them genera Bacillus spp., Rhodococcus spp., Flavobacterium spp., Xanthomonas spp., were most abundant; In addition, 26% of clones showed less than 96% of 16S rRNA gene identity with bacterial sequences deposited in GenBank database. Besides, rarefaction curve reaches clear saturation and its Coverage C value is 93%, indicating that most of the estimated endophytic bacterial diversity was sampled and 249 positive clones for enzyme digestion were enough good to the community investigation. These results suggest that Achnatherum inebrians harbors a diversity of cultivable endophytic bacteria and maybe existence of some potential novel species or lineages.