The Er3+ and Er3+/Yb3+ co-doped bismuth glasses were prepared in this work. The absorption spectra and fluorescence spectra of the glasses were measured at room temperature. The strength parameters calculated according to the Judd-Ofelt theory from the absorption spectra are Ω2=(5.47—2.92)×10-20 cm2，Ω4=(2.16—1.22)×10-20 cm2, and Ω6=(1.29—0.80)×10-20 cm2. The absorption cross section at 980 nm and intensty of emission spectra at 1.5 μm were compared. FWHM of the broad fluorescence band of Er3+/Yb3+ co-doped bismuth glass at 1.5 μm is 91 nm, which is 15 nm larger than that of Er3+-doped bismuth glass. Emission cross section of σe=1.00×10-20 cm2 has been obtained using McCumber theory. The optical properties of Er3+ ion in bismuth-based glass are discussed by comparing with other glasses. The results show that Er3+ dopingof bismuth based glass is highly preferable for optical amplifier to realize broadband high gain amplification.