Nanocomposites are a new class of composites in which the reinforcing phase dimensions are on the order of nanometer scale. In particular, the layered silicates are considered to be good candidates for the preparation of polymer-inorganic nanocomposites. The mechanical and thermal properties of polymer can be altered by adding a few vol% of the nano-particles. The effect of the nano-sized particles on thermophysical properties such as melting and crystallization, coefficient of thermal expansion, and thermal conductivity was studied. After preparing the PEMA/layered silicate nanocomposites, the thermophysical properties were investigated by the differential scanning calorimetry and 3ω methods. The content of layered silicate was varied from 0.5 to 5 vol%.