The bacterial diversity of two deep-sea sediments collected at Lau Basin hydrothermal vents were analysed by performing a restriction fragment length polymorphism (RFLP) analysis of 16S rRNA gene sequences. Analysis of sequences showed that there were a diversity of bacterial populations in sediments from Lau Basin deep-sea hydrothermal vents, and six bacterial divisions and four bacterial divisions represented in the sample DY1 and DY2 respectively. The phyla Gammaproteobacteria and Epsilonproteobacteria were the most dominant groups in both clone library DY1 and DY2. Additionally, some bacterial sequences had lower similarity to most known sequences in the database, which suggested that there were some novel taxa of bacteria in sediment from Lau Basin deep-sea hydrothermal vents.