In this study, a nanocomposite of 80 run alpha-Al2O3-incorporated polypyrrole (PPy) film was electropolymerized on a An substrate. It was found that the nucleation and growth were instantaneous three-dimensional processes before and after nuclei overlapping for pure PPy electropolymerization. However, a distinguishable nucleation and growth mechanism before nuclei overlapping was shown for the preparation of the nanocomposite. The nanocomposite demonstrates an extremely high oxidation level revealed from the analyses of X-ray photoelectron spectroscopy (XPS) and surface-enhanced Raman scattering (SERS). Also the conductivity of the nanocomposite was increased substantially ( similar to 5.4 times) and it can depress aging in a 50% relative humidity, 20% (v/v) O-2 and 30 degreesC atmosphere for 60 days, in comparison to pure PPy.