A synthetic route for the preparation of a novel solution copolymer derived from styrene (St), pyrrole (Py) and its organoclay nanocomposite with conductive and mechanical properties is demonstrated. The electroactive copolymer of polystyrene-g-polypyrrole (PSt-g-Ppy) nanocomposite was successfully prepared by atom transfer radical polymerisation (ATRP) and chemical polymerisation methods. First, potassium pyrrole was reacted by a-chlorophenyl acetyl chloride to prepare an initiator that can polymerise styrene by ATRP technique. Then, polypyrrole was prepared by chemical polymerisation using FeCl 3 as an oxidant in dichloromethane , s solvent. Nanocomposites of the copolymer with modified montmorillonite were prepared with a solution intercalation method. The conductivity of the copolymer was measured by the four-point probe method. The structures of the intermediate, copolymer and nanocomposite were investigated by Fourier transform infrared spectroscopy, 1 H-NMR and X-ray diffraction techniques. The molecular weight of the copolymer was determined by gel permeation chromatography. Their thermal behaviour was examined by differential scanning calorimetry and thermogravimetric analyses.