The submerged arc nanosynthesis system for preparing Cu-based nanofluids with different morphologies and using various dielectric liquids has been developed. Pure copper is selected as the electrode as well as the workpiece material. Copper is heated and vaporized by arc sparking between two electrodes being immersed in dielectric liquids. The copper aerosol can be condensed to form nanoparticles immediately by the cooling media (dielectric liquids). The nanoparticles then dissolve in the dielectric liquids which become metal nanofluids. Various morphological Cu-based nanoparticles can be synthesized using different dielectric liquids. The effects of experimental parameters and dielectric liquids on the characteristics of final products have been investigated. The possible formation mechanism of Cu-based nanoparticles via the faster growing faces is suggested. (c) 2005 Elsevier B.V. All rights reserved.