Bundle-shaped TbPO ₄ ·H ₂ O nanorods have been prepared by a facile hydrothermal technique and characterized by XRD, SEM, TEM, UV-Vis diffuse reflectance spectrum (DRS), photoluminescence (PL) spectrum, and lifetime. The results indicate that the obtained sample has hexagonal structure of TbPO ₄ ·H ₂ O and is composed of nanorods bundles which is assembled from many single crystalline nanorods with the diameter of around 45 nm and the length of 2.3 μ m. The growth of the single crystalline nanorod is along the (001) plane direction. Under the UV light irradiation, TbPO ₄ ·H ₂ O nanorods bundles exhibit bright green emission corresponding to the D 5 4 → F 7 J ( J = 6,5 , 4,3 ) transitions of the Tb ³⁺ ions, and the lifetime is determined to be about 0.24 ms.