Abstract: We have prepared a series of polypropylene/ graphene oxide (PP/GO) nanocomposite via melt compounding and investigated their morphology, structures, thermal stability and mechanical properties as a function of GO content. For this purpose GO as reinforcing nanoscale fillers, is prepared by the oxidation process of natural graphite flakes. SEM images and X-ray diffraction data confirm that the GO platelets are well dispersed in PP matrix for the nanocomposites with GO contents less than 2.0 wt% and PP-g-MA improved its dispersion. Electrical resistivity of the nanocomposite films dramatically changed from ~1016 to ~107 Ω•cm by forming electrical percolation threshold at GO content between 1 and 3 wt %. Tensile drawing experiments demonstrate that yielding strength and initial modulus of PP/EG nanocomposite films are highly improved with the increment of GO content. The composites exhibited noticeable improvement in thermal stability in comparison to pure PP. Keywords: Nanocomposite, Graphene Oxide, Mechanical Properties, Morphology