The electropolymerizition of polyaniline (PANI) on Pb substrate was performed by potentiostatic or galvanostatic method in aniline＋oxalic acid electrolyte. The PANI coatings were characterized by FTIR, XRD and SEM methods. The results showed that the PANI coatings have a crystalline-amorphous composite structure whose degree of crystallinity is about 30%~50%. They belong to a conducting emeraldine salt form and contain varied amounts of water (hydrated PANI salt). The PANI coating synthesized at low current density is in a more reduced state. There is a fibrillar-like morphology for the PANI coatings electrodeposited on Pb substrate.