The tetra-needle like zinc oxide whisker (T-ZnOw) was treated with gamma-aminopropyltriethoxysilane (APTS), a coupling agent of silane with amino-group, to form a protection and bonding layer on its surface, where polyaniline (PANI) was in situ polymerized to form a new kind of core-shell structured T-ZnOw/PANI composites. The structure, morphologies, and conductivity of the synthesized products were characterized by Fourier transform infrared spectroscopy (FTIR). X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis absorption spectroscopy, etc. The FTIR spectra reveal that the T-ZnOw is successfully modified by APTS and finally forms the T-ZnOw/PANI core-shell structure composites. The SEM results indicate surface modification plays distinct roles both for keeping the intactness of the morphology structure of T-ZnOw and for providing an in situ polymerization site on the surface of the T-ZnOw. The electrical conductivity of the PANI covered T-ZnOw is 7.2 x 10(-1) S cm(-1), which appears much higher than that of the pure T-ZnOw. (C) 2008 Elsevier B.V. All rights reserved.