Polyaniline doped with hydrochloric acid (HCl) was prepared by chemical oxidative polymerization of aniline (ANI) in aqueous medium with ammonium peroxy disulphate as an oxidant. The deprotonation of the PANI: HCl samples were performed by stirring the PANI: HCl powder (emeraldine salt) in 0.1 M aqueous solution of ammonium hydroxide for 24 hours at room temperature, thus obtaining the polymer in the emeraldine base form. The redoping of the PANI (emeraldine base) with para- toluene sulphonic acid was performed by mixing emeraldine base (EB) with para- toluene sulphonic acid (PTSA) to obtain the required doping levels (Y = 0.5, Y =0.3, Y =0.1), known as the molar ratio of TSA to phenyl-nitrogen repeat units (S/N).The prepared samples were characterized by Fourier transform- infrared (FT-IR) spectroscopy, Ultraviolet- Visible (UV-VIS) spectroscopy and X-ray diffraction technique.The prepared samples were pressed into pellets, and DC electrical conductivity was measured, using four-probe method. The FT-IR peaks obtained in the samples are in good agreement with the reported peaks in literature. UV-VIS spectroscopy shows the various electron transitions present in the polyaniline samples. The crystallinity of the samples was studied in detail by X-ray diffraction technique.The conductivity shows an increase with increase in temperature, for all the three samples.