One dimensional LaPO4:Eu nanowires with different ratio of length to width (10-30) were synthesized by hydrothermal method and studied. The results indicated that there existed two crystalline sites and their relative proportion changed with the variation of the ratio of length to width. It is significant to observe that luminescent quantum efficiency of Eu3+ increased linearly with the increase of the ratio of length to width. (C) 2004 Elsevier B.V. All rights reserved.