Unique negative giant magnetoresistance (GMR) of up to -43% at room temperature was observed in the 10 wt% titania/polyaniline (TiO2/PANI) nanocomposites prepared by simple oxidation polymerization. And the negative MR value was further evaluated using forward interference model. Other properties were tested and comparatively reported. The resistivity of TiO2/PANI nanocomposites decreased with increasing temperature, indicating a semiconductor behavior. The Mott variable range hopping (VRH) approach indicated that TiO2/PANI nanocomposites are disordered systems in the 3-dimensional VRH regime. The scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) were also used to study morphology, chemical and crystal structure of the nanocomposites. The thermogravimetric analysis (TGA) was used to study the thermal stability of the TiO2/PANI nanocomposites. (C) The Author(s) 2016. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives 4.0 License (CC BY-NC-ND, http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium, provided the original work is not changed in any way and is properly cited. For permission for commercial reuse, please email: oa@ electrochem.org. All rights reserved.