The glycidyl methacrylate (GMA) and styrene (St) multi-monomers melt grafted PP, PP-g(GMA-co-St), was used as a reactive compatibilizer of PA6/PC blends in this study. The effect of the addition of PP-g-(GMA-co-St) on compatibility of the blends was investigated. It was found that the addition of PP-g-(GMA-co-St) greatly reduced the MFR values of the PA6/PC, implying enhanced compatibility between PA6 and PC in the presence of the PP-g-(GMA-co-St). The phase morphologies of the blends with increasing content of PP-g-(GMA-co-St) were observed by SEM. The particle size of PC decreased with increasing content of PP-g-(GMA-co-St) in the blend. Much finer dispersion of discrete polycarbonate phase with average domain size 0.2 mum was reached when the content of the PP-g-(GMA-co-St) was 10% (PA6/PC, mass ratio 72/28). This should be due to the formation of the PA6-PP-PC copolymer by chemical reactions between GMA in PP-g-(GMA-co-St) and the terminal amino or carboxylic groups of PA6 and between GMA in PP-g-(GMA-co-St) and terminal -OH group of PC during the melt extrusion process. The formation of PA6-PP-PC copolymer is also characterized by FTIR. The mechanical properties of the PA6/PC blends, particularly the Izod impact strength and elongation at break were markedly improved by addition of a small amount of PP-g-(GMA-co-St). It should be noted that tensile strength of the PA6/PC/PP-g-(GMA-co-St) was also kept with increasing PP-g-(GMA-co-St) content. The PA6/PC blends with balanced mechanical properties can be obtained by addition of PP-g- (GMA-co-St).