Highdensity SiOx nanowires were fabricated on a largescale using carbonassisted 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 Xray spectral analysis reveals that the nanowires consist of Si and O elements in an atomic ratio of approximately 1∶18The nanowires show IR absorption peaks at 482,806,1095 and 1132 cm-1. The PL peak of the nanowires is located at 440 nm （283eV）.The PL inensity of the SiOx nanowire （N2） is 104 times that of the SiOx nanowire（N2/NH3）.