Ti/Sn1–xIrxO2 electrodes were prepared on titanium substrates by thermal decomposition method. The structure and the surface morphologies of the electrodes were characterized by XRD, SEM, and the electrochemical properties were investigated by linear scan voltammetry. The results showed that in NaCl solution and Na2SO4 solution, with increasing the Ir content, the potential gap of electrochemical oxidation（△E）between chlorine evolution and oxygen evolution decreased. The electrode containing 30% Ir (by mol%) had the highest chlorine evolution efficiency. Using Ti/Sn0.7Ir0.3O2 electrode as anode, a simulated wastewater with p-chlorophenol as pollutant was degraded by constant current electrolysis. The degradation rate of p-chlorophenol in presence of NaCl was faster than in presence of Na2SO4.