Abstract: The research and exploitation of special microbial resources in extreme environment is of scientific significance and has broad applied prospect. In this paper, eight Bacillus strains isolated from the vegetation rhizospheres in Kekexili extreme region of Qinghai Province and presented good growth status at low temperature 4 and 10 ℃ were identified. Through physiological and biochemical analysis,
rep-PCR fingerprinting, and 16S rDNA and gyrB partial sequence analyses, the eight strains were identified as Bacillus mojavensis (3 isolates), Bacillus amyloliquefaciens (1 isolate), and Bacillus simplex (4 isolates). The agar plate antagonistic test showed that four of the isolates presented distinct antagonistic activity to Sclerotinia sclerotiorum and Xanthomonas oryzae pv. oryzae. The MALDI-TOF-MS analysis showed that the strain KKD-1 (B. mojavensis) produced fengycin and surfactin, whereas the strain KKD-2 (B. amyloliquefaciens) produced iturin A, surfactin and fengycin, suggesting that the biocontrol efficacy of the Bacillus strains could be related to the synthesis and excretion of the antifungal lipopeptide compounds. This study provided the bacterial resources for the research and exploitation of low temperatureadapted Bacillus biofertilizers and bio-pesticides.