Abstract: Carbon nanotubes (CNTs) were functionalized by polytetrafluoroethylene and fluorinating CNTs (F-CNTs)/epoxy composites were prepared by ultrasonication and mold casting method. As a comparison, raw CNTs and F-CNTs have been characterized by using FTIR, XRD, TEM. The results showed that C–F bonds were created on the side wall of CNTs, successfully synthesized F-CNTs. The F-CNTs could form stable suspension solutions in organic solvents, which disperse easily in polymers. Their impact strength and flexural strength of F-CNTs/epoxy composites were investigated with different content of F-CNTs. The results show that when the content of F-CNTs is 1.5wt%, the impact strength and flexural strength are 25.85kJ/m2、128.1MPa, respectively.