The bacteria in adult female body of Culex quinquefasciatus were analyzed with PCR–DGGE. The analysis process were as follows: grinding the adult female of Culex quinquefasciatus in a sterile condition, and extracting the total genomic DNA; then amplifying the 16S rDNA V3 with universal primers, and separating the V3 fragments through DGGE electrophoresis, followed by cloning, sequencing and blasting. The results showed that the six species of the bacteria were carried by the adult female Culex quinquefasciatus, one of them was Wolbachia pipientis, other five species, have not been identified, were belong to Pseudomonas sp., Escherichia sp., Wolbachia sp., alpha proteobacteria and Gamma proteobacterium.