Abstract: The syndiotactic polystyrene nanocomposite according to the present invention has nano silicate materials dispersed individually in a styrene polymer matrix by intercalation and exfoliation during polymerization. Besides, the syndiotactic polystyrene nanocomposite according to the present invention is prepared by using a catalytic system composed of a phyllosilicate-supported Group IVB transition metal catalyst and alkylaluminoxane, wherein the phyllosilicate-supported Group IVB transition metal catalyst comprises: a) a polymer, b) a phyllosilicate and c) a Group IVB transition metal compound, and the polymer (a) is used as an insulating material or media of the phyllosilicate (b) and the Group IVB transition metal compound (c).