Terbium-doped zinc oxide nanocrystalline are successfully prepared by Sol-Gel process.Photoluminescence spectrum (PL) and Photoluminescence spectrum excitation (PLE) of nanocrystalline ZnO: Tb³⁺ with excitation wavelength 368 nm are measured at room temperature. The luminescence process of Tb³⁺-doped zinc oxide nanocrystalline has been investigated by using PL and PLE. Emission of ⁵D₄→⁷F₆(485 nm),⁵D₄→⁷F₅(544 nm),⁵D₄→⁷F₄(584 nm) and⁵D₄ →⁷F₃(620 nm) of Tb³⁺ ions,and weak and wide visible band of ZnO were observed. An energy transfer from excited states of ZnO hosts to doped Tb³⁺ ions centers is disclosed by the fact that Photoluminescence intensity of the maximum of nanocrystalline ZnO : Tb³⁺ on doping concentration of Tb³⁺ ions increases.