Due to the indirect band gap structure,the light emission efficiency of SiC materials is usually very low,which limits the applications of SiC in optoelect ronic devices.A lot of methods have been employed to improve the light emission efficiency of SiC materials,of which synthesizing SiC nano-structure materials would be an effective way.In our work,SiC/SiO_2core-shell nanowires were synthesize d on Si (100) substrate by the reaction of methane with silicon dioxide using iron as catalyst.The structural properties of the nanowires are characterized by scanni ng electron microscopy (SEM),transmission electron microscopy (TEM) and X-ray diff raction (XRD).It can be seen that the nanowires have a diameter about 50nm and length about 10μm,a nd the nanowires consist of a 30nm single-crystal β-SiC core and a 10nm amorphous SiO_2shell.The light-emitting properties of nanowires are studied by photoluminescence spectroscopy.A sharp ultraviolet peak at 380nm and an intens ive broad green band with defined maximum peak at 505nm are observed in PL spectra of as-grown nanowires.According to analysis,the ultraviolet peak originates f rom the oxygen-vacancy defects in the SiO_2shell and the broad green band comes from the SiC cores caused by quantum confinement effect.