Abstract: Graphene oxide (GO) was synthesized through a modified Hummers method from graphite flakes. Then tridecafluorooctyl triethoxysilane modified reduced graphene oxide (FAS-RGO) was obtained by reducing the GO functioned with FAS. And the composite films of poly(vinylidene fluoride-co-hexafluoropropylene)(P(VDF-HFP)) incorporating FAS-RGO were prepared by a solution-cast method. FTIR, XRD, XPS, Raman and TEM were employed to characterize the structure of FAS-RGO. Meanwhile, the effect of FAS-RGO content on the dielectric property of FAS-RGO/P(VDF-HFP) was discussed. The results show that FAS layer is coated on RGO surface, which can solve the problem of accumulation of RGO effectively. FAS layer also increases interfacial combination of the FAS-RGO/P(VDF-HFP) composite films and improves the dispersion of RGO in the matrix. The FAS-RGO could nucleate the P(VDF-HFP) crystallization and induce the formation of β phase. A dielectric constant of FAS-RGO/P(VDF-HFP) is up to 62 at 100 Hz, which is 5.2 times that of pure P(VDF-HFP) film. In this case, FAS-RGO/P(VDF-HFP) composite films show low dielectric loss when the concentration of FAS-RGO is 1.6vol%.