Polymer/silicate nanocomposites were prepared via two-step manufacturing process: a master batch preparation and then mixing with matrix polymer. A hybrid of PMMA and Na-MMT with exfoliated structure was first prepared by emulsion polymerization of MMA in the presence of Na-MMT. For the case that SAN24, miscible with PMMA, is used as matrix, we could prepare a nanocomposite with exfoliated structure. However, SAN31 nanocomposite shows the aggregation and/or reordering of the silicate layers due to the immiscibility between SAN31 and PMMA.