Plywood sheets based on wood plastic nanocomposites were prepared using palm tree fibers (PTF) filled in polystyrene (PS) nanocomposites. The nanocomposite sheets were prepared using free radical polymerization of styrene monomer containing 60 % PTF and different nanosilica concentrations. The effect of coupling agent on the adhesion between PTF and PS/SiO2 nanocomposites and PTF was pronounced at low nanosilica concentrations. The results of the flexural strength, impact test, abrasion resistance, and water absorption were explained on the basis of the effect of coupling agent between PTF and nanocomposite resin.