The (SiO2/Si/SiO2) nanoscale double-barrier/n+- Si structures with Si layers of various thicknesses were fabricated by the two-t arget alternative magnetron sputtering technique. The thicknesses of the Si laye rs in the structures are from 2nm to 4nm with an interval of 0.2nm. The control samples with Si layers of 0nm were also made. After these structures were anneal ed at 600℃ in a N2 ambient for 30min, electroluminescence (EL) from the Au/SiO2/Si/SiO2/n+-Si structures were obser ved under reverse biases (n+-Si is biased to positive). It was found that the current and EL intensity synchronously swing with increasing Si layer t hickness. All EL spectra of the samples can be decompounded into two Gaussian lu minescent spectra with peaks at 1.85eV (670nm) and 2.26eV (550nm). Analysis of e xperimental results indicates that the EL orginates from the recombination of el ectrons and holes, which are produced in an avalanche process in the Au/(SiO2/Si/SiO2) nanoscale double-barrier/n+-Si structure , via luminescence centers in the SiO2 layers.