A series of Si-N or Eu-Li doped CeAl11O18 and CeAl12O18N phosphors are prepared by solid–state reaction. Their structure and luminescence are researched carefully. Si-N doping with the concentration less than 8% can be successfully dissolved into CeAl11O18 crystal lattice and doesn't change the matrix structure, only resulting in crystal lattice shrinkage due to the shorter bond length for Si–N bond versus Al–O bond. It is observed that blue emission gradually decreases and UV emission becomes stronger due to the gradual disappearance of OMe ions with the increase of Si-N doping. Compared with the traditional UV emitting phosphor CeMgAl11O19, Si-N doped CeAl11O18 shows better thermal stability. The crystal structure and lattice parameters of Eu-Li codoped CeAl11O18 remain unchanged due to the large tolerance of rare-earth sites. On account of the energy transfer from UV emission of Ce3+ to Eu2+, a single overlapping blue emission with high intensity is obtained in Eu-Li codoped CeAl11O18 phosphor.