Long (15-40 μm),thin (diameter of 20 ± 5 nm),and well-dispersed CuNWs Cu nanowires were prepared.The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline.To investigate the growth mechanism,we examined the microstructure of these CuNWs at different reaction time.It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [11 0] direction.The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 ％ at 3 1±5 Ω/□.