Transparent Er3+/Yb3+ co-doped lead fluosilicate glass ceramics is prepared, which contains nano crystalline with size of 10—12 nm. The up-conversion emission in oxyfluoride glass ceramics is notably stronger than that in its glass counterpart. The green luminescence intensity of the 2 H11/2（4S3/2）→4I15/2 transition and the red luminescence intensity of 4F9/2→4I15/2 transition in the glass ceramics are 26 and 6 times stronger than those in its glass counterpart, respectively. The ratio of the green emission intensity to the red one for the lead fluosilicate glass ceramics decreases abviously, while it is almost a constant for the lead fluosilicate glass. It is believed that the low phonon energy in nanocrystallines and the changed energy transfer properties result in the enhancement of the up-conversion emission and the variation of the up-conversion spectra.