A combination of theoretical and experimental methods, including DFT calculation, BET, Raman spectroscopy, NH3-TPD, H-2-TPR and XPS, has been used to elucidate the mechanism of lead deactivating effect on the V2O5 based SCR catalyst. The theoretical calculations have shown that the doping of lead atom will cause the great change of the surface electronic property. Each lead atom will influence two active sites, resulting in the decrease of the acid formability and reducibility of the catalyst surface. The NH3-TPD and H-2-TPR experiments have shown the decrease of acid site amount and reducibility, which is in accordance with the calculation result. The BET result has also shown the physical influence caused by the doping of lead compound. The NO conversion experiment has confirmed the deactivation effect of lead on the V2O5 based catalyst. (C) 2011 Elsevier B.V. All rights reserved.