Uniform NaLuF4 nanowires and LuBO3 microdisks have been successfully prepared by a designed chemical conversion method. The lutetium precursor nanowires were first prepared through a simple hydrothermal process. Subsequently, uniform NaLuF4 nanowires and LuBO3 microdisks were synthesized at the expense of the precursor by a hydrothermal conversion process. The whole process was carried out in aqueous condition without any organic solvents, surfactant, or catalyst. The conversion processes from precursor to the final products have been investigated in detail. The as-obtained Eu3+ and Tb3+-doped LuBO3 microdisks and NaLuF4 nanowires show strong characteristic red and green emissions under ultraviolet excitation or low-voltage electron beam excitation. Moreover, the luminescence colors of the Eu3+ and Tb3+ codoped LuBO3 samples can be tuned from red, orange, yellow, and green-yellow to green by simply adjusting the relative doping concentrations if the activator ions under a single wavelength excitation, which might find potential applications in the fields such as light display systems and optoelectronic devices.