The transparent geramanate glass ceramics with a mole composition ratio of x(GeO2):x(Al2O3):x(NaF):x(CaF2):x(ErF3)=54:20:6:20:2 have been prepared.The luminescence properties were studied.Using two-step heat treatment,the CaF2 crystals with nanometer size,could be formed in the matrix glass.Excitated by 980 nm LD,the upconversion luminescence intensities of Er3+ ions are significantly higher for the transparent glass ceramics than for the glass,whereas 1.5 μm emission is weaker.The transition is related to two-photon absorption for red (4F9/2→4I15/2) and green (4S3/2→4I15/2) luminescence,and three-photon absorption for blue (2H9/2→4I15/2) luminescence.The Er3+-doped transparent oxy-fluoride germanate glass ceramics is a kind of active optical material with excellent properties.