Variation of crystallographic growth direction and twinning structure of Cu nanowires (NWs) is achieved by a pulsed-current deposition method with anodic aluminum oxide templates. With increasing applied current density and decreasing deposition temperature, the grown Cu NWs showed an enhancement of (111) crystallographic texture and a downward shift in twin lamella width distribution. The mean value of twin width distribution is down to 6.5 nm for the Cu NWs deposited at -2 degrees C and at a pulse current density of 0.8 A/cm(2). A mechanism based on surface diffusion kinetics and relaxation of deposition-induced stress is proposed to explain the change of growth texture and twinning structure of Cu NWs with varying electrodeposition parameters. The study provides a route to the development of nanotwinned copper interconnects technology for advanced micro- and nano-electronic devices. (C) 2013 The Electrochemical Society. All rights reserved.