Abstract: Graphene aerogel (GA) was prepared by sol-gel chemistry, and then GA/epoxy (EP) composites were prepared by sonicate-mixing method. The structure of GA was characterized by SEM, N₂ nitrogen sorption tests, XPS and XRD. In addition, the effects of GA mass fraction on the thermal property and the conductivity property of the GA/EP composites were also investigated. The results indicate that the GA shows a three-dimensional network of randomly oriented graphene sheets with wrinkled texture, and is rich in pores. After thermal reduction, the specific surface area of GA increases to 731.84 m² ·g^-1, the interlayer spacing of the graphene decreases to 0.347 nm, and the oxygen-containing functional groups are almost all removed. DMA and electrical conductivity testing results show that with the increase of GA content, T_g of GA/EP composites increases first and then decreases, and the electrical conductivity increases with the percolation threshold of 0.05%-0.3%.