Abstract：The dominant bacteria were isolated from sea cucumbers released in Jincheng area in Laizhou and Muping area where the massive death of the sea cucumber caused by environmental factors had been oc-curred by plate-separation method ,and identified by 16S rDNA universal primer of bacteria ,by cloning , sequencing ,and RDP sequence alignment successively .The results showed that the 13 dominant bacterial strains were within 5 genera ,Paracoccus ,Planococcus ,Lucibacterium ,Vibrio and Agarivorans ,Vibrio bacteria accounting for 53 .8% .Dominant bacteria were correlated with the physiological function of sea cucumber and the aquaculture environment conditions .There were different dominant bacterial species in the samples collected from different areas ,more percentage of Vibrio in Laizhou area than that in Muping area ,w hich may be involved in the difference in V ibrio status in the culture environment .
