Highdensity SiOx nanowires were fabricated on a largescale using carbonassisted CVD method by Fe—Al—O catalyst at 1140℃ in flowing N2/H2,N2 and NH3 atmospheres.The SiOx nanowires have uniform diameters of 20—300 nm and lengths of up to a few hundred micrometers. SEM, TEM, EDS, FTIR and PL were preformed to characterize the microstructure, composition and optical performance of the nanowires. Energy dispersive Xray spectral analysis reveals that the nanowires consist of Si and O elements in an atomic ratio of approximately 1∶18The nanowires show IR absorption peaks at 482,806,1095 and 1132 cm-1. The PL peak of the nanowires is located at 440 nm (283eV).The PL inensity of the SiOx nanowire (N2) is 104 times that of the SiOx nanowire(N2/NH3).