A polychlorinated biphenyls-degrading bacterium DN2, using biphenyl as sole carbon source and energy source, was isolated from long-term PCBs-contaminated soil. Through morphological observation and sequence analysis of 16S rDNA, the strain was identified as Pseudomonas sp.. By identification of bphA1 core segment of biphenyl dioxygenase (BPDO) and enzyme activity assay of 2, 3-dihydroxybiphenyl-1,2-dioxygenase, the PCBs/biphenyl degradation-related genes in the bacterium was confirmed. Using GC-MS and resting cells PCBs degradation capacity test, the strain could remove 67% of the Aroclor 1242 in 3 days with 30%-90% of degradation rate of Aroclor 1242 congeners, which can contribute to the in situ bioremediation for the PCBs contaminated field.