A simple solution route was introduced for the fabrication of uniform mesoporous EuF 3 nanospheres by using Eu(NO 3 ) 3 and ionic liquids ([BMIM]BF 4 ) as the starting reaction reagents at room temperature under ambient pressure without any surfactants and templates. The mesoporous samples were characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, as well as N 2 adsorption–desorption. The mesoporous EuF 3 nanospheres are composed of tiny nanocrystals with a size of ca. 5nm. The time dependent studies of the reactions have been conducted to reveal the morphological evolution of mesoporous EuF 3 nanospheres. An intensive emission peak at around 592nm was observed at room temperature for the mesoporous EuF 3 nanospheres due to the 5 D 0 – 7 F 1 magnetic-dipole transition of Eu 3+ ions.