SBS-g-MWNTs/carbon fiber/epoxy (SBS-g-MWNTs/CF/EP) three-phase composite laminates were fabricated to study the effect of styrene-butadiene-styrene triblock copolymer grafted multi-walled carbon nanotubes (SBS-g-MWNTs) on mechanical performance of carbon fiber-reinforced composite. The chemical grafting of styrene-butadiene-styrene (SBS) on multi-walled carbon nanotubes (MWNTs) was characterized by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), transmission electron microscopic (TEM) and thermogravimetric analysis (TGA). The mechanical properties of SBS-g-MWNTs filled CF/EP composites were evaluated by tensile, flexural, impact and interfacial shear strength (ILSS) tests. Results showed that SBS-g-MWNTs was homogeneously dispersed in epoxy matrix and the existence of SBS-g-MWNTs effectively strengthened the interfacial adhesion between carbon fiber and epoxy, leading to remarkable enhancement in impact strength by 90.2% and ILSS by 99.7% of the composites with as low as 0.50 wt.% SBS-g-MWNTs, along with other improved mechanical properties. [GRAPHICS] .