A series of phosphors SrBPO5:R,Na+ (R = Eu3+, Tb3+) were prepared by high-temperature solid-state synthesis, and their phase purity, morphology, IR spectra, and UV-Vis photoluminescence properties were investigated. The f-f transitions of Eu3+ and Tb3+ ions in the host lattice were assigned and discussed. The excitation and emission spectra indicate that SrBPO5:Eu3+,Na+ and SrBPO5:Tb3+,Na+ can be effectively excited by ultraviolet (394 and 370 nm), and exhibit reddish orange emission and yellowish green emission, respectively. The influence of the doping concentration on the relative emission intensity of Eu3+/Tb3+ was investigated, and the critical distance Rc was estimated in term of the concentration quenching data. The present study suggests SrBPO5:R,Na+ (R = Eu3+, Tb3+) phosphor can be a potential candidate as an UV-convertible phosphor for white light-emitting diodes (LEDs).