PANI nanotubes were successfully prepared by using thin glass tubes as a single template in the presence of H(4)SiW(12)O(4)0 and ammonium persulfate, which were used as dopant and oxidant, respectively, in this system. The structure and morphology of the PANI were characterized by IR spectrum, XRD pattern, SEM images, and TEM images. The inner diameter of PANI nanotubes was between 50 and 100 nm. This method employed here was a simple and effective way to prepare multifunctional PANI nanotubes. The gas response of the PANI nanotubes to a series of chemical vapors such as NH3, N2H4, and (C2H5)(3)N was studied. The results indicate that the PANI nanotubes show superior performance as chemical sensor.