The visible emission of BaMgAl₁₀O₁₇:Eu²⁺ used for White LED and ACPDPs was enhanced by coupling electric transition with the localized surface plasmon oscillation of nanoscaled Ag particles. Phosphor films including Ag particles were prepared by the spin-coating method. Up to a 36% enhancement of the peak intensity, which was dependent on the morphology and concentration of Ag particles, was obtained. It was verified that the spectral overlap between the LSP energy of metal particle and the emission spectra of phosphor materials decided between the enhancement and quenching of the emission. It was indicated that localized field enhancement due to the LSPR of metal nanoparticles could improve the emission intensity of phosphor doped rare earth ions.