Quasi-spherical LuBO3 nanoparticles have been successfully synthesized by a designed hydrothermal conversion method. The Lu(OH)CO3 nanoparticles were first prepared by a simple homogeneous precipitation method. Subsequently, LuBO3 nanoparticles were synthesized at the expense of the Lu(OH)CO3 nanoparticles during a hydrothermal conversion process. The conversion process from the Lu(OH)CO3 precursor to LuBO3 nanoparticles was investigated by time-dependent experiments. Moreover, the as-obtained Eu3+ and Tb3+-doped LuBO3 products show strong characteristic red and green emissions under ultraviolet excitation and low-voltage electron beam excitation, respectively. This work sheds some light on the knowledge of conversion of different kind of lutetium compounds, and the luminescent properties have potential applications in fluorescent lamps and field emission displays. More importantly, this simple method is expected to allow the large-scale production of other complex rare-earth compounds with controllable morphologies and sizes, and exploration of the morphology and photoluminescence properties. (C) 2013 Elsevier Ltd. All rights reserved.