LaF3∶Tb3+, Ce3+ nanocrystals were prepared with hydrothermal method with the help of cetyltrimethyl ammonium bromide (CTAB). The effects of pH values of the solution, Ce3+/Tb3+ ratio value and reaction time on the luminescent properties were investigated. XRD analysis shows that the as-prepared samples possess hexagonal phase and their main diffraction peaks of samples are similar to the standard card (JCPDS 32－0483). Compared with pure LaF3, the main diffraction peaks of the doped samples have a slight shift, showing existing isomorphous substitution between La3+ and the doped rare earth ions in parent lattice of LaF3. It is found from TEM results that the as-prepared samples have good crystallinity and their average grain sizes change in the range of 20～50 nm. The excitation spectra indicate that the stronger excitation spectrum peaks exist at 250 nm, which is assigned to the transition of 4f→5d from Ce3+. When activated at 250 nm, all LaF3∶Tb3+, Ce3+ nanocrystals possess weak blue emission at 490 nm (electric dipole transition, 5D4→7F6) and good green emission at 543 nm (magnetic dipole transition, 5D4→7F5). As the Ce3+/Tb3+ ratio increases, the fluorescence intensities increase at first and then weaken, and reach the strongest green emission at nCe3+/nTb3+=4. The pH values have some influence on the colors and intensities of the LaF3∶Tb3+, Ce3+ nanocrystals. The sample prepared at pH　9 presents the best color, while the one at pH 7 exhibits the strongest green emission. Besides, increasing reaction time is helpful to improve color purity of sample and enhance its green emission.