The fabrication of syndiotactic polystyrene (sPS)/organophilic clay nanocomposite was conducted via melt intercalation process. To obtain sPS nanocomposites with exfoliated clay, the stepwise mixing process using RPS as amorphous styrenic polymer was adopted. Also, organophilic clay modified by cetyl pyridium chloride was used to overcome the thermal instability of commonly used clay and to enhance the compatibility of clay with sPS. We could obtain exfoliated sPS nanocomposites in all compositions without any collapsed clay layers. The microstructures of nanocomposites were confirmed by X-ray diffraction and transmission electron microscopy. The crystallization rate of nanocomposites investigated by differential scanning calorimetry increases with the content of clay, which may be due to the nucleating effect of the clay layer. Nanocomposites exhibited enhanced stiffness relative to the neat polymer. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012