The influence of Yb3+ content on structural evolution and fluorescence properties of oxyfluoride glass ceramics containing LaF3 nano-crystals were systematically investigated. Differential scanning calorimetry (DSC) and transmission electron microscopy (TEM) experiments indicated that Yb3+, ions acted as nucleating agent to facilitate LaF3 crystallization. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) results verified the incorporation of Yb3+ into LaF3 nano-crystal lattice. The absorption, emission spectra and fluorescence decays were measured. The infrared emission intensity of F-4(5/2) -> F-4(7/2) transition under 980 nm excitation enhanced, while the measured lifetime reduced due to the increase of non-radiative transition probability, with the increase of Yb3+ content in glass ceramic. However, when Yb3+ doping reached 4.0 mol% the concentration quenching effect appeared. (c) 2006 Elsevier B.V. All rights reserved.