The PbO2 and F-doped PbO2 (F-PbO2) film electrodes have been prepared by an electrodeposition process onto platinum substrate. The changes of their electrochemical activity for oxygen evolution (OE) reaction with accelerated electrolysis time have been studied. The results show that the activity of the electrodes decreases with increasing electrolysis time. This can be attributed to the conductivity variations, which are caused by the decrease of the oxygen vacancy concentration in PbO2 films during OE. The mechanism of the decrease of the oxygen vacancies has been investigated. For F-PbO2 film electrodes, though its electrochemical activity is somewhat lower than that of undoped one, its activity stability is much higher in comparison with that of PbO2. The influence of F- doping on the activity of PbO2 film electrodes has been also discussed. (C) 2007 Elsevier Ltd. All rights reserved.