The decomposition of 2,4',5-trichlorobiphenyl as a derivative of PCB was studied by means of the injecting the solution into NaOH-Na2CO 3 or KOH-K2CO3 molten salts. The solution of 2,4',5-trichlorobiphenyl dissolved in an organic solvent were fed into the molten salts together with the carrier gas (N2-21%O2) through the injection tube. The experiments were carried out in the temperature range of 500-700°C by immersing the injection tube into the molten salts. Potassium system showed relatively higher decomposition efficiency than sodium system at low temperature. The decomposition efficiency of 2,4',5- trichlorobiphenyl depended on the temperature and was approximately 99.999% over 600°C in both systems. copyright The Electrochemical Society.