In this paper, the glycidyl methacrylate( GMA) was grafted to Polypropylene( PP) macromolecular backbone by melt radical grafting. The grafted PP-g-GMA was used to compatibilize PP/SEBS-g-MAH blend in a Haake apparatus. The result of Fourier Transform Infrared( FTIR) spectrum showed that the GMA had been grafted to PP. And the reaction between epoxy groups in the GMA and MAH groups in SEBS-gMAH had taken place. The result of torque test showed that the torque values of the compatibilized blends were higher than that of the uncompatibilized blends. The observation of Scanning Electron Microscopy ( SEM) showed that the dispersed phase domain size of compatibilized blends decreased evidently than uncompatibilized blends. When the content of SEBS-g-MAH was 16 wt% and the PP-g-GMA was 2 wt% in the blend, the rubber particle size had a minimum value. Those indicated that the PP-g-GMA could compatibilize PP/SEBS-g-MAH blends effectively. Notched Izod impact tests showed the addition of PP-g-GMA in the PP/SEBS-g-MAH blends induced a remarkable improvement of toughness and yielded a tougher PP blends.