Two strains,named as XA1 and XB1 utilizing naphthalene as the sole carbon source,were isolated from Zhanggong Dam of Jinkou in Wuhan City.XA1 and XB1 were both identified as Pseudomonas fluorescens through morphological characterizations,physiological and biochemical identification and alignment analysis of the 16S rDNA sequence.Their optimal growth temperature were both 28℃ and the optimal growth pH value were 7.5 and 7.0,respectively.When XA1 and XB1 were inoculated in the liquid inorganic salts medium with naphthalene as the sole carbon source,the degradation rates of naphthalene after three days were 93.4% and 74.7%,respectively.Catechol 2,3-dioxygenase gene and some other genes were characterized with the PCR method and agarose gel electrophoresis.Results showed that sequences of catechol 2,3-dioxygenase gene and the others all possessed 99% similarity with the sequences in the NCBI.