NaGdF4 nanocrystals with controlled shapes were synthesized in an ethylene glycolldeionized water hydrothermal reaction system. Through adjusting the solvent composition, the nanocrystals with nanosphere-, nanotube-, and nanorod-like morphology have been selectively synthesized. The change in the nucleation speed, the growth rates in different crystallographic direction and the aggregation driving forces induced different morphologies of the resulting nanocrystals. A possible mechanism of shape evolution depending on solvent composition was proposed. Photoluminescence spectra of NaGdF4:Nd3+ nanocrystals exhibited characteristic emission of Nd3+ using an excitation wavelength of 794 nm. Moreover, the nanotube-like nanocrystals exhibited the strongest fluorescence intensity and longest fluorescence decay time. (C) 2016 Elsevier B.V. All rights reserved.