Bacterial community and diversity in marine sediment from Cangnan Large Fishing Bay (27°19′57.3″N, 120°34′28.6″E) were investigated by combining culture-independent with culture-dependent methods. By the culture-independent method, DNA was extracted directly from the environment. Molecular library containing bacterial 16S rRNA gene was constructed. 25 clones were selected and the cloned 16S rRNA gene fragments were sequenced. Finally, 18 sequences were phylogenetically analyzed based on the 16S rRNA gene. The sequenced clones fell into five phylums of the domain Bacteria: Proteobacteria, Firmicutes, Chloroglexi, Nitrospirae and Acidobacteria, and most of them shared relatively low similarity with described bacteria. The results revealed that the library was dominated by Gammaproteobacteria and Deltaproteobacteria of Proteobacteria. By the culture-dependent method, 79 bacteria strains were isolated. The 16S rRNA gene sequences were determined and analyzed. Most of the isolates were closely related to described bacteria, and fell into three lineages: Alphaproteobacteria and Gammaproteobacteria of Proteobacteria, and Bacilli of Firmicutes. However, some sequences showed low affiliation with the sequences from described species (less than 97%), suggesting the presence of some novel taxa. The sequences from culture-independent and culture-dependent methods were assigned to operational taxonomic units (OTUs) based on sequence analysis. Subsequent analysis using Shannon index indicated that the bacterial diversity from the culture-independent method was significantly higher than that from the culture-dependent method. Integrated the results of culture-independent with culture-dependent methods, the Gammaproteobacteria and Deltaproteobacteria were the dominant bacterial groups in sediment from Cangnan Large Fishing Bay.