In this study, the copolymers of methyl methacrylate-co-glycidyl methacrylate (MGD) with different epoxy contents and molecular weights, the styrene-co-glycidyl methacrylate (SGD) and methyl methacrylate-co-maleic anhydride (MAD) were synthesized. The synthesized copolymers, styrene-co-maleic anhydride (SMA) and styrene-acrylonitrile-co-glycidyl methacrylate (SAG) were used as compatibilizers to enhance the impact strength of the acrylonitrile butadiene styrene/poly(butylene terephthalate) (ABS/PBT). The effects of differences in the structure, reactive group type, and molecular weight of the compatibilizers on the mechanical properties, phase morphology, melt viscosity, thermal stability, and melting temperature of the blend were studied. The results showed that functionalized copolymers were successfully synthesized with high monomer conversions. Addition of the functionalized copolymers increased melt viscosity but did not considerably affect thermal stability, tensile strength, flexural strength and melting temperature of the ABS/PBT blends. The compatibilizers improved the dispersion of the PBT phase and prevented brittle fracture, thereby increasing the impact strength of the blend. Among the studied compositions, the ABS/PBT/MGD-5 blend exhibited the highest impact strength of 25.8 kJ/m(2)and an appropriate melt flow index of 19.1 g/10 minutes. The compatibilizer should have an appropriate molecular weight to improve the interface bonding force. Regarding the melting viscosity, the reactive group content and compatibilizer dosage should be adjusted to ensure high impact strength.