The conductive polypyrrole (PPy) is intercalated into the interlayers of expanded vermiculite (EVMT) to produce the nanocomposite with high conductivity by a synchronous polymerization of pyrrole and intercalation of PPy reaction in aqueous solution. The structures and properties are characterized by the nanocomposite using powder X-ray diffraction, Fourier transform infrared spectroscopy, conductivity measurements, and stability measurements. The nanocomposite exhibited a typical percolation phenomena and the percolation threshold is around mass ratio for pyrrole to EVMT 0.22. Under optimized conditions, a PPy/EVMT intercalated nanocomposite with conductivity of 67 S cm(-1) is obtained. The intercalated nanocomposite has a good environmental stability. (C) 2008 Wiley Periodicals, Inc. J Appl Polyrn Sci 110: 2862-2866, 2008