ABSTRACT In this article epoxy based polypyrrole nanocomposites were prepared using solution mixing approach and the effect of nanofiller loading level on the mechanical and thermal properties of final nanocomposites were studied. For this porpose PPy nanoparticles synthesized by chemical oxidative polymerization of pyrrole monomer and used as reinforcement. FTIR analysis demonstrated that PPy nanoparticles successfully synthesized. Mechanical analysis using tensile test demonstrated that mechanical properties depended on the concentration of PPy nanoparticles and there is a optimized concentration (2 % wt) that for it, mechanical properties such as Young’s modulus and tensile strength are higher than other nanocomposites. Thermal properties analysis using TGA analysis demonstrated that thermal stability of nanocomposites improved by the addition of PPy content. Keywords: Nanocomposite, Epoxy resin, Polypyrrole (PPy), Mechanical and Thermal Properties