Abstract: A serial montmorillonite (MMT)/polypyrrole (PPy) composites (MMT/PPy) were prepared by vapor-liquor phase polymerization of pyrrole vapor with Fe³⁺ impregnated MMT suspension. It was found that the polymerization of pyrrole took place within the silicate layers of MMT. XRD of MMT/PPy composites showed that the basal spacing of MMT layers increased with increasing the PPy content. FTIR of MMT/PPy exhibited both characteristic adsorption peaks of MMT and PPy，while some peaks appeared blue shift. The obtained MMT/PPy displayed flake like morphology. Even after etching of MMT from MMT/PPy by HF，the resultant PPy still displayed a flake-like morphology，which was very different from the inherent globular PPy obtained by the same method. The conductivity of MMT/PPy became higher with increment of the PPy content. When the PPy content reached 40.9 wt%，the composite possessed almost the same conductivity as PPy. Furthermore，the composite containing 54.3 wt% PPy even showed a higher conductivity than PPy. This phenomenon might be attributed to the special morphology of the PPy in composite，which was caused by in situ polymerization within a confined space of MMT layers.