Abstract: It is difficult for nano-SiO2 to combine with polymer to form a strong combine, due to small size,high surface energy and easy to reunite.In this thesis,firstly,PP/SiO2 masterbatches were prepared after the surface processing of nano-SiO2 with silane coupling agent and dispersant,then PP/SiO2 composite materials were prepared by extrusition with maleic anhydride grafted PP as compatilizers.The results showed that the tensile strength of composite materials up to 44.7MPa,the notched impact strength up to 21.9kJ/m2,which had increased by 49% and 158% compared with pure PP separately. Consequently,the composite materials can replace ABS in the automotive,household and other industries.