Abstract: Amorphous SiO_x:C films were prepared by Dual Ion-beams Sputtering Deposition（DIBD） with the composite target of Si and C on the quartz glass（SiO₂）.Intense photoluminescence（PL） at 420nm and 470nm from the film was observed at room temperature and the PL intensity enhances with increasing annealing temperature.Comparing with the PL spectrum of Si-SiO₂ film,the luminescent mechanism of the SiO_x:C film was discussed subsequently.The PL peak at 470nm is usually ascribed to neutral oxygen vacancy（O₃≡Si-Si≡O₃） and the peak at 420nm is related to doping with C,which possibly formed a complex structure with Si and O in the film.