The Er3+-Bi3+ co-doped borate glasses are fabricated by the method of oxide high-temperature melting. The absorption and emission spectra are studied. The intensity parameters Ωλ (λ=2,4,6), determined by Judd-Ofelt theory, are calculated to be Ω2=3.8249×10-20 cm2, Ω4=1.6805×10-20 cm2 and Ω6=1.5069×10-20 cm2, respectively. The spectral intensity of the electric dipole transitions, the spontaneous radiative transition probabilities and the absorption cross-sections are also calculated. The full width at half maximum (FWHM) and stimulated emission cross-sections of 4I13/2→4I15/2 transition are calculated by McCumber theory. The results show that the FWHM of Er3+-Bi3+ co-doped borate glasses can reach 69.68 nm.