A systematic investigation on fluorescence spectroscopy of trivalent thulium doped in oxyfluoride glass ceramics containing LaF3 nanocrystals has been carried out in a spectral range from 400 to 900 nm under the direct excitation of 1D2 level at a low temperature.Specific optical transitions related to the fluorescence emissions are studied based on experimental measurements in frequency and time domain.Fluorescence emissions from the ions in crystal phase are distinguished from what in glass phase and their spectroscopic properties are explored.The dynamical process shows that the temporal decay of fluorescence emission consists of two parts:a rapid decay from the ions in glass phase and a slower decay from the ions in crystal phase.