LaOF:Eu3+ nanoparticles were successfully prepared by annealing LaF3:Eu3+ nanocrytsals which were capped with SiO2 shell. The SiO2 shell effectively prohibited the growth of LaF3:Eu3+ nanocrystals during the annealing process, and it was etched off after annealing to obtain the LaOF:Eu3+ nanoparticles. The LaOF:Eu3+ nanoparticles had a size comparable to the original LaF3:Eu3+ nanoparticles. Inorganic-organic hybrid nanoparticles of LaF3:Eu3+ and LaOF:Eu3+ nanoparticles with thenoyltrifluoroacetone (TTA) ligands were prepared. Strong luminescence as a result of the energy transfer from the TTA organic ligands to the LaF3:Eu3+ and LaOF:Eu3+ nanoparticles was observed. The LaOF:Eu3+-based hybrid nanoparticles exhibited stronger luminescence intensity and broader excitation spectral range than the LaF3:Eu3+-based hybrid nanoparticles. Effect of the content of TTA ligands on the luminescence of the LaOF:Eu3+ nanoparticles was investigated in detail.