Sm 3+ - and Eu 3+ -doped rare-earth borate glasses (Li 2 O–BaO–La 2 O 3 –B 2 O 3 ) have been fabricated and characterized optically. The density, refractive index, optical absorption, Judd-Ofelt parameters, and spontaneous transition probabilities have been measured, calculated and analyzed. Sm 3+ and Eu 3+ emit intense reddish-orange and red lights under blue and UV light excitations, respectively. In Sm 3+ and Eu 3+ co-doped glasses, the excitation wavelength range of Eu 3+ emission is broadened owing to the energy transfer from Sm 3+ to Eu 3+ . This broadening makes the Ar + 488nm wavelength laser a powerful excitation source for Eu 3+ fluorescence. The rare-earth doped glasses with various visible emissions are useful for developing new color light sources, fluorescent display devices, UV-sensor and tunable visible lasers.