Conductive polyaniline (PAn)/kaolinite composite was prepared by in situ chemical polymerization by using potassium dichromate as oxidant. The changes in the conductivity and PAn content of composite with reaction conditions Such as aniline/oxidant mole ratio, temperature and HCl concentration were investigated The PAn content and conductivity of the composite reached to the maximum Values of 7.3% and 24.6 x 10(-3) S cm(-1), respectively. The resistivity of PAn/kaolinite composite was followed during the cooling-heating cycles repeated between 5 and 120 degrees C and observed to increase with increasing temperature. The structure and the morphology of the composite were elucidated by FTIR, XRD,TGA and SEM techniques SEM micrographs revealed that PAn was dispersed in composites as particles. The change of conductivity and microhardness values of the composite with its PAn content were also investigated (c) 2009 Elsevier B.V. All rights reserved