There is a distinct micro-ecosystem in polar region due to its peculiar geographic and climate characters.According to the distinct morphological characters of bacterial clones on marine Zobell 2216E medium plate, a total of 571 strains were obtained from marine sediments collected during the 5th Chinese National Arctic Expedition between July and September ,2012.Molecular identification and phylogenetic analysis showed that these isolates belonged to four phyla of the bacteria domain, 5 classes, 47 genera and 102 species in total.Fourteen strains had 16S rRNA gene similarity less than 97％ with the closest type strain, and it indicated that these isolates might be potential novel species.