Abstract: Silane coupling agent (APTES) was used as functional monomer to modify oxidation graphene(GO) and three kinds of silane coupling agent modification of GO (APTES-g-GO) nano-fillers have been prepared firstly under different experimental conditions. Then polystyrene (PS) composites filled with APTES-g-GO were fabricated by melt blending. To improve the compatibility of the blends, maleic anhydride grafted polyolefin (POE-g-MAH) was used as a compatibilizer. The morphology and properties of nano-fillers and the resultant nano APTES-g-GO/POE-g-MAH/PS composites have been characterized in detail by means of FTIR, XRD, TG, SEM, tensile and impact tests. The results indicate that APTES was successfully grafted onto the surface of GO. APTES shows some exfoliation and reduction effects to GO. Tensile strength and impact strength of the nano APTES-g-GO/POE-g-MAH/PS composites increase firstly, followed by decreasing with increasing nano-fillers content, and reach a maximum value at the 0.75% mass ratio of nano-filler content. Among them the nano AS-GO/POE-g-MAH/PS composites achieve the best comprehensive performance. The tensile strength and impact strength increase by 19% and 31%, respectively, compared with those of POE-g-MAH/PS. The reactions between the APTES-g-GO and POE-g-MAH take place during the blending process, which improve effectively the interfacial interactions of blending systems. APTES-g-GO disperse well in the composites. APTES-g-GO improve the thermal stability of composites, especially for the composite filled by AS-GO. The maximum thermal loss temperature of nano AS-GO/POE-g-MAH/PS composite with 0.75% mass ratio of AS-GO increases by 7 ℃ compared with that of POE-g-MAH/PS.