Copper electrical wire explosion experiments were conducted in water, and the elementary process of wire explosion was analysed according to the measured current and voltage waveforms. It was found that the current changed from an interrupt status to a second breakdown with the increasing density of the deposited energy. The purity of the nanocopper particles prepared in water was more than 91.3%, which was detected by X-ray diffraction. The statistical analysis of the particles size was completed according to transmission electron microscope images. The statistical data shows that the particle sizes mainly distributed over 10-40 nm and 80-180 nm, as analysed with the bubble pulse theory and Leidenfrost phenomenon. (C) 2015 Elsevier B.V. All rights reserved.