Abstract: To classify degradation rule of parathion in strong acidic electrolyzed water(AcEW),kinetic model and products of degradation reaction of parathion in strong acidic electrolyzed water(AcEW)were studied in this paper. Results showed that with the increasg of the reaction time and available chlorine concentration,the degradation efficiency of parathion was increasing in AcEW. Degradation reaction in AcEW was in accord with the chemical reaction kinetics. The first-order kinetic equation of degradation reaction in strong acidic electrolyzed water(AcEW)were ln(parathion_t/parathion₀)=-0.0099t. Degradation products of parathion in AcEW could be paraoxon and 4-nitrophenol by GC-MS analysis. The possible degradation pathway of parathion in AcEW could be parathion-paraoxon-4-nitrophenol-small molecular-inorganic matter.