The reaction between lignin and the surface oxide layer on Pb plates was studied by dipping experiments in ultra pure water with lignin, anodic polarograms in sulfuric acid solution with or without lignin and also scanning electron microscopy (SEM) observations of the sample surface after anodic polarization. It is found that the lignin reacts with the surface oxide on the Pb plates in ultra pure water with lignin to reaction products containing Pb and the lignin and they grew preferentially at the interface between Pb and the surface oxide. The deposits formed on the surface suppress to passivate the Pb surface under sulfuric acid solution. (C) 2003 Elsevier B.V. All rights reserved.