Hierarchical beta-NaGdF4 nanobundles are synthesized through a facile hydrothermal method with the use of sodium acetate (NaAc). A NaGdF4-GdF3-NaGdF4 products transformation with the increase of fluoride source (NaF) is observed. Results show that NaAc is the key factor in the synthesis of beta-NaGdF4 at a low NaF/Gd3+ ratio and NaAc also plays a significant role in the formation of the hierarchical morphology. Meanwhile, the size of nanobundles increases with the increased ratio of NaF/NaAc. With altering the ratio of reactants, dumbbell-like, urchin-like or rod-like beta-NaGdF4 nanobundles are obtained. The photoluminescent properties of beta-NaGdF4: 2%Eu3+ are also measured. (C) 2017 Elsevier B.V. All rights reserved.