[Objective] The aim of this study was to understand the relationship between the diversity of culturable bacteria in the surface seawater and the hydrological environment.[Methods] We used MA, R2A and seawater medium to isolate bacteria from four different hydrological environments:the warm area, the cold area, the basin area and the intersection area. 16S rRNA was sequenced for classification and identification of the isolates, and phylogenetic tree was built for phylogenetic analysis.[Results] In total 407 bacteria were isolated from the samples and 154 strains were selected and sequenced by the Restriction Fragment Length Polymorphism analysis. These 154 strains were divided into 3 phyla, 18 genera and 27 species. The 3 phyla were Proteobacteria, Firmicutes and Actinobacteria. The dominant genera were Pseudoalteromonas,Psychrobacter, ect. The dominant species were Pseudoalteromonas agarivorans,Psychrobacter nivimaris, ect. And several psychropliles bacteria were separated such as Alteromonas fuliginea. Compared the bacterial diversity among different regions, γ-proteobacteria was dominant in all the four areas, and the bacterial diversity of intersection area was the highest, where 10 different genera were isolated. Bacterial diversity of basic area was the lowest, only had 4. In addition to the basin area, special species were isolated from the samples in other 3 areas.[Conclusion] Nordic Sea is rich in microbial resources, and the microbial diversity in the intersection area is higher than that in other regions.