Poly(ethylene terephthalate) (PET) and polypropylene (PP) and are incompatible and have been well recognized. In this study, styrene-butadiene copolymer (SBC) compatibilizer in the blends PET/PP. Compatibility of PET/PP blends was studied by mechanical properties and morphology. When integrating all the investigations of compatibility compared with the mechanical properties, it is possible to conclude that SBC promotes a certain level of partial compatibilization for several of PET/PP blends.