The compositions of lead anodic layers and structure strongly depends on, additives, concentration of sulfuric acid, and on potential region. A phenomenon of anodic excursion peaks was always in focus of many researches. In this work the behaviour of anodic excursion peak (AEP) in 0.5 M H2SO4 solution is widely investigated by dynamic electrochemical impedance spectroscopy (DEIS), atomic force microscopy (AFM) and cyclic voltammetry (CV) methods. The changes of the impedance spectra and AFM images as a function of potential are presented in this paper. it is suggested that the occurrence of anodic excursion peaks cannot be caused by oxidation of bare metal induced by cracking, it can be related to the oxidation of anodic layer to the oxides with higher non-stoichiometric coefficient. (C) 2009 Published by Elsevier B.V.