Polyaniline (PANI) composite nanotubes (90-130 nm in diameter) containing titanium dioxide (TiO2) nanoparticles (about 10 nm in diameter) were synthesized through a self-assembly process in the presence of beta-naphthalenesulfonic acid (beta-NSA) as the dopant. It was found that the morphology, size, conductivity, and hydrophobicity of the PANI-beta-NSA/TiO2 Composite nanotubes were affected by the content of TiO2 nanoparticles in the nanotubes. The micelles composed of beta-NSA anions and anilinium cations containing TiO2 were proposed to interpret the formation mechanism of the self-assembled composite nanotubes. The Raman spectra and X-ray diffraction characterizations show that the main chain of the composite nanotubes is identical to that of the doped PANI, and indicate that there is no chemical interaction between PANI and TiO2.