The structure change and failure behavior of Ti/SnO 2+Sb 2O 3/PbO 2 anodes were studied during the electrolysis process in 1.0 mol·L -1 H 2SO 4 solution.The morphology,microstructure and the electrochemical behavior of the anodes in the different electrolysis processes were examined by means of XRD,SEM,CV and EIS.The variation of cell potential went through three stages:“instability”,“stability”and“rapid rising”in the whole electrolysis process.The morphology,microstructure and the electrochemical behavior of the anodes changed obviously in these stages.In the later stage of the electrolysis process,the passivation film of TiO 2 between the Ti substrate and the oxide coating was formed and PbO 2 coating peeled from the electrode,which caused the inactivation of electrodes.