The distribution and laser-induced behaviour of PbO on lead electrodes have been investigated using photoelectrochemical microscopic (PEM) and cyclic voltammetric techniques. A linear relationship between the potential of the reduction peak for lead monooxide and the pre-oxidation time of the electrodes was obtained at low potential-sweep rates. This result implies that the changes of pH within the inner anodic films could be estimated using the electrochemical method. Some interesting photocurrent characteristics of "laser-induced" oxide "islands" have been observed. In addition, a linear growth mode of PbO has been found at an early stage of growth of the anodic films using a "line-scan" method in the PEM technique.