Abstract: The influence of silane coupling agents and grafting modification of polypropylene (PP) matrix on the mechanical properties of continuous glass fibre reinforced polypropylene (CGFRPPs) was studied. The interfacial chemical action and interfacial adhesion in the silanized GF/modified PP were also investigated using FTIR and SEM. The results showed that there is chemical action between the modified PP blended with maleic anhydride grafting PP (MAH g PP) and the silanized GF, which obviously increases the interfacial adhesion and mechanical properties of the composites, and silane coupling agents of different kinds make not much difference to the mechanical properties of GF/PP composites with grafting PP in the matrix.In addition, it was found that improvement of MAH g PP on the mechanical properties of CGFRPPs is superior to that of acrylic acid grafting PP.