Copolymer EPM-g-GMA were prepared by grafting glycidyl methacrylate (GMA) on to EPM in a co-rotating twin-screw extruder．The grafting yield of EPM-g-GMA copolymers was determined by FTIR measurements．The morphology and mechanical properties of PBT blended with EPM-g-GMA were studied．It was found that the increase of the GMA content in the graft copolymer may reduce the particle size of the dispersed phase in the blends of PBT／EPM-g-GMA and improve the cohesion between the component of the blends．The results show that the particle size of the dispersed phase was about 0.5 mm

when the GMA content in the graft copoymer used for blending was 4.7 phr (grams per 100 grams of EPM)．At the same time the izod notch impact strength of the PBT/EPM-g-GMA blend reached 51.6 kJ/m2

which is 31 times as high as that of pure PBT．