This study uses molecular dynamics simulations with an embedded-atom method (EAM) potential to investigate the effects of strain rate on a copper wire in tension at the nanoscale. By averaging the atomic stresses over the entire system, the stress-strain curves for the nanowire were predicted. The results show that an elastic region clearly exists in the early deformation of the copper nanowire and the elastic modulus is about two times of the value measured at the macroscale. The yield stress of the nanowire increases with the strain rate. Moreover, the evolution of the crystal structure was investigated in terms of the radial distribution function and the local atomic order was also examined by the common neighbour analysis. The dislocations and recrystallization processes inside the nanowire have been observed. The simulated results reveal the process of the fracture of copper nanowire in tension.