Abstract: A total of 55 strains with antagonistic activities against tobacco pathogen Ralstonia solanacearum were screened from 600 endophytic bacteria isolated from three tobacco varieties,which were NC297,Hongda and K326.Bioassay results in vitro showed that these antagonists exhibited different antibacterial activities to the pathogen with inhibited hole of 1—16 mm in diameter.The 55 antagonists were represented by 6 RFLP patterns.16 representative isolates,1—3 strains from each RFLP patterns,were selected for 16S rRNA sequencing.Phylogenetic analysis placed the 55 antagonistic bacteria into 6 species of Firmicutes and Proteobacteria : Bacillus amyloliquefaciens subsp. plantarum,Bacillus methylotrophicus,Bacillus tequilensis,Brevibacillus parabrevis,Brevibacillus brevis and Pseudomonas aeruginosa .Three species of endophytic bacteria, ( Brevibacillus parabrvis, Brevibacillus brevis and Pseudomonas aeruginosa ) showed chemotactic activity by methods of cheA gene amplification and plate assay.