Facial synthesis of cuprous oxide (Cu2O) nanowires by directly heating copper substrates is difficult; however, in this study, it was successfully done by thermal oxidation followed by a plasma reduction process. The preparation of CuO nanowires with an average diameter of 76.2 nm supported on the surface of copper substrate was conducted first in air at 500 A degrees C for 3 hrs, and then the CuO nanowires were reduced into Cu2O in 15 min using either radio frequency (RF) N-2 plasma or microwave (MW) N-2 plasma. The characteristics of CuO and Cu2O nanowires were analyzed using XRD, FE-SEM, and TEM. The results showed that Cu2O nanowires can be successfully reduced from CuO nanowires by a simple, promising, and fast nitrogen plasma process. Moreover, in RF plasma, narrower and longer Cu2O nanowires can be produced as compared to MW plasma, because energetic N-containing species can reduce the nanowires at a relatively lower temperature.