Abstract: The attapulgite (ATP) and graphene oxide (GO) were modified with silane coupling agent KH560, and they were composited to obtain the ATP-GO hybrids. Then the ATP-GO/epoxy resin (EP) composites were prepared by in-situ polymerization using the EP as the matrix. The morphology and chemical structure of the ATP-GO hybrids were characterized by SEM and FTIR. The results show that ATP and GO are successfully composed with ATP attached on the surface of GO. The impact strength, bending strength and thermal stability of the ATP-GO/EP composite are enhanced by incorporation of ATP-GO hybrid fillers, whereas the dielectric constant and the dielectric loss are reduced. The bending strength and impact strength of 3wt%ATP-0.5wt%GO/EP composites reach 138.58 MPa and 20.80 kJ/m², which are 75.5% and 351.6% higher than that of the pure EP, respectively. While the dielectric constant and dielectric loss of ATP-GO/EP composites decrease to 3.36 and 0.0118, which are 7.7% and 27.3% lower than that of the pure EP.