Polyaniline/TiO 2 nanocomposites was prepared in the presence of titanium dioxide. The incorporation of polymers in the composites was proved by FTIR studies. The nanocomposites have been characterized by four point probe conductivity measurements, UV Vis, transmission electron micrograph. The results show that polyaniline/TiO 2 has a higher conductivity(×10 -2 ) compared with that of EB, the UV Vis spectra properties of polyaniline/TiO 2 depend on the ratio of TiO 2 to polyaniline. The UV Vis spectrum of the nanocomposites doped with HCSA shows a red shift and possesses a higher conductivity and better solubility compared with those of nanocomposites and PANI. TEM micrographies show that TiO 2 nanoparticles are partly coated with the polymer.