LuYAP:Ce is mixed crystal of YAP:Ce and LuAP:Ce, possessing the features of short decay time, high light yield, high density and effective atomic number, no deliquescence. The shorter decay time，higher density and effective atomic number display with lutetium component increasing. The crystal boule with 35 mm×100 mm has been succesfully grown by Czochralski method，which is transparent, no phasedecomposition. The element component was determined by XRF method. The Lu/Y ratio was close to 7∶3. The light output was also measured before and after crystal annealed. An increase of 16% was obtained.