Abstract: Phosphate radio-photoluminescence dosimeter glasses with five different molar ratios of Li/Na (7∶0, 5∶2, 1∶1, 2∶5, 0∶7) were prepared by conventional melt-quenching method. The effects of mixed alkali oxides on glass chemical stability and the predose of dosimeter were investigated. The best chemical stability was achieved at Li/Na molar ratio of 5∶2. However, the dosimeter has the maximal predose when the Li/Na molar ratio is 2∶5. Because of ionic radius r_Na⁺＞r_Li⁺ and chemical bond Na—O＜Li—O, the cut-off wavelength is red-shifted when Li-2O is replaced by Na-2O. The glass density increases with the increment of Na-2O. Under 337 nm UV light excitation, the fluorescence intensity increases with the increment of Na-2O. Electron paramagnetic resonance test indicates that the build-up time decreases with the increment of Na-2O. For the application of glass dosimeter, the suitable glass composition can be chosen according to the results.