The effects of nutritional sources on growth of Pseudomonas sp. P2 were investigated in medium containing biphenyl as a carbon source. To determine characterization of Pseudomonas sp. P2, the incubation time was determined to 100 h of the log phase in the growth curve. The optimal compositions for the growth of Pseudomonas sp. P2 degrading polychlorinated biphenyls (PCBs) were 1000 ㎎/L NH4NO3, 1000 ㎎/L KH2PO4, 100 ㎎/L MgSO4·7H2O, 30 ㎎/L CaCl2·2H2O, 200 ㎎/L NaCl, and 10 ㎎/L FeSO4·7H2O. Pseudomonas sp. P2 showed the degradability of 59.3 %, 57.6%, 51.4%, and 48.7% at 500 ㎎/L, 1000 ㎎/L, 1500 ㎎/L, and 2000 ㎎/L of the PCBs within insulating oil after 100 h incubation under the optimum conditions, respectively.