During bioenhanced activated carbon(BEAC)process,the inoculated bacterial communities are dynamic.For solving this problem,bacteria with biodegradability and competitive power must be isolated.DGGE profiles of BAC filter indicated that there were 4 dominant bacteria,and 2 of them could degrade organ-ic pollutants,which were Pseudomonas sp.and Bacillus subtilis.Thirty five bacteria were isolated from BAC filter using LB medium.Target probe of Pseudomonas sp.and Bacillus subtilis were designed for testing domi-nant bacteria quickly.After fluorescence in situ hybridization(FISH),5 dominant bacteria were identified and they were SRO 2(Pseudomonas stutzeri),SRO 11(Pseudomonas putida),SRO 19(Pseudomonas pertucinogena),SRO 20(Pseudomonas balearica)and SRO 30(Bacillus subtilis),respectively.The biodegradation test of organic pollutants in Songhuajiang water showed that the 5 bacteria could degrade organic pollutants.Dehydrogenase activities in these 5 bacteria were higher than other isolates,so that these five bac-teria were valuable bacterial resource for applying in BEAC process.