Abstract: The experimental equipment used for synthesizing nanopowders via the sub-microseconds electrical explosion of wire was built based on the short discharge circuit of a pulsed capacitor. The particle morphology of the nanopowder was observed by the transmission electron microscope (TEM). The particle size and distribution of the nanopowders were obtained based on the statistics and observation of TEM images. Aluminum nanopowders were produced by electrical exploding aluminum wire in the argon gas, and the influence of the deposited energy on the characteristics of aluminum nanopowders was studied by changing the charging voltage of the capacitor. The results show that the morphology of aluminum nanopowders was mainly dependent on the argon gas pressure rather than deposited energy, and high deposited energy could also narrow the particle size distribution of aluminum nanopowders and reduce the count mean diameter of nanoparticles under the same argon gas pressure. It is indicated that charging voltage of the capacitor is an influential factor in eliminating submicrometer particles. The count mean diameter, the maximum diameter and the fraction of particles with diameter greater than 100 nm of aluminum nanoparticles decrease exponentially with the increasing expansion volume parameter (Ep-1).