The resistivity, breakdown strength, and formation of space charges are very important factors for insulation design of HVDC cable. It is known that a nano-sized metal-oxide inorganic filler reduces the formation of space charges in the polymer nanocomposite. Electrical conduction of cross-linked polyethylene(XLPE) nanocomposite insulating material is investigated in this paper. The conduction currents of two kinds of XLPE nanocomposites and XLPE without nano-filler were measured at temperature of 303 ~ 363 K under the applied electric fields of 10 ~ 50 kV/mm. The current of the nanocomposite specimen is smaller than that of XLPE specimen without nano-filler. The conduction mechanism may be explained in terms of Schottky emission and multi-core model.