Polymer/clay nanocomposites have attracted considerable attention as a method of enhancing polymer properties and extending their utility. Polymer/clay nanocomposites can be fabricated by various methods such as in-situ polymerization, solution drying, and melt intercalation. In this study, Poly(styrene-co-acrylonitrile)/clay nanocomposites were prepared using a emulsion polymerization. The properties were investigated as a function of clay content (5,8,10,15 wt%) in the SAN matrix. X-ray diffraction (XRD) and Transmission electron microscopy (TEM) photographs showed that most clay layers were dispersed homogeneously into the matrix polymer in nano-scale, although some particles of clay were agglomerated. The Dynamic mechanical analysis (DMA) measurement shows that the storage modulus of nanocomposites is higher than that of the clay-free SAN.