ECA (electrochemical-assembly), a new method for preparing nano-ordered conducting polymer films is reported A nano-ordered conducting film of polyaniline / p-aminothiolphenol (PANI/PATP) is constructed by this new technique. The proper-ties, structure and surface topography of the polymer film of PANI/PATP are investigated by surface enhanced Raman scattering (SERS), scanning tunneling microscopy (STM) and cyclic voltammetry. The results indicate that the close packed PANI/ATP film is flat, uniform and ordered.