Abstract: Aluminum nanoparticles have broad application prospects. Electrical explosion of wires(EEW) is an important way to produce aluminum nano-particles efficiently. To improve the production efficiency of nano-particles, the characteristics of electrical explosion and nano-particles size distribution of Al wires with higher initial mass(length 7~15 cm and diameter 0.1~0.4 mm) in voltage 20~30 kV and argon pressure 100~300 kPa were studied. The influences of length and diameter of Al wire, charging voltage, and argon pressure on the voltage and current waveforms in the process of EEW were obtained. The corresponding relationship between energy deposition and overheat coefficient with the size distribution of nano-particle was established. The results show that when the length and diameter of Al wire increase, the energy deposition per unit volume will decrease, the average particle size of nanoparticles will increase, and the proportion of particles larger than 100 nm will significantly increase. When the Al wire parameters are constant, increasing the charging voltage can increase the energy deposition per unit volume and decrease the average particle size of the nano-particles. Argon pressure has a negligible effect on the energy deposition and size distribution of nano-particles.