A sample of emission-line high-luminosity galaxies from the Sloan Digital Sky Survey (SDSS) was investigated. Line intensities in 116 SDSS spectra of 99 galaxies were measured. The oxygen abundances in the galaxies were determined. Since the auroral line of doubly ionized oxygen [O III] λ 436.3 nm is not detected in the spectra of the objects from our sample, the temperature-sensitive nebular-to-auroral line ratios are derived from the ff-relation. The obtained oxygen abundances in high-luminosity SDSS galaxies are lower by 0.2—0.5 dex than the maximum attainable value. This is caused by the fact that our sample of SDSS galaxies contains only gas-rich galaxies with strong star formation bursts. The equivalent number of O7 V stars exciting the radiation of H II regions in galaxies from our SDSS sample exceeds by two-three orders the equivalent number of O7 V stars which excite the radiation of the brightest H II regions in nearby galaxies and exceeds by one order the equivalent number of O7 V stars exciting the gas radiation in SBS 0335-052 E.