[en] The luminescence behaviors of Er³⁺ doped glass ceramics containing Sr₂RF₇ (R=Y,Gd,La) nanocrystals were investigated. The formation of Sr₂RF₇ nanocrystals in the glass ceramics was confirmed by x-ray diffraction and high resolution transmission electron microscopy. Energy dispersive x-ray spectroscopy analysis showed that the Er³⁺ ions were efficiently incorporated in Sr₂GdF₇ nanocrystals. The efficient upconversion luminescence of the Er³⁺ in the glass ceramics can be observed. The lifetime of the Er³⁺ in the glass ceramics was found to be much longer than that in the glass due to the lower phonon energy of fluoride crystals when Er³⁺ entered efficiently fluoride crystals in the glass ceramics