This review summarizes the structure of clay minerals, the preparation of synthetic layered silicates, organo-layered silicates and polymer-clay nanocomposites. In particular, the prospects and advantages of synthetic layered silicate-polymer nanocomposites are discussed. Synthetic layered silicates afford a high degree of controllability of purity, morphology, aspect ratio, and surface properties through the control of synthetic conditions. These designed layered silicates promise better fine-tuning of polymer-organoclay interactions, and therefore enhanced opportunities to produce well-exfoliated nanocomposites. The synthetic layered silicate-polymer nanocomposites could be applied to optical, electronic, film and medical products requiring high purity.