The mechanical properties of the polypropylene/nano-SiO2 composite before and after heating treatment were discussed and the effects of the crosslinking agent and the elastomer on the mechanical character of the nano-composite were explored. The results showed the tensile strength, tensile modulus and impact strength of the material increased respectively by a factor of 10% , 30% and 80% comparing with that without nano-SiO2. The tensile and impact strength of the composite has been further improved after h...