The absorption spectra,emission spectra and thermal stability of Er3+-doped (85-x)Bi2O3-(10+x)B2O3-5Na2O(x=0,5,10,15,20,25 mol%)glasses were investigated in this work.The Ωt(t=2,4,6)(Ω2=(352—386)×10-20cm2,Ω4=(138—152)×10-20cm2，Ω6=(093—117)×10-20cm2)parameters were calculated by Judd-Ofelt theory.The stimulated emission cross sections(σe=(70—95)×10-21cm2)of the Er3+ ion 4I13/2→4I15/2 transition were calculated using the McCumber theory.The FWHMs(FWHM=57—79nm) of the 4I13/2→4I15/2 emission and lifetimes of 4I13/2 level(τm=265—159ms)of Er3+ ions were measured.The thermal stability of the glasses were analyzed.The compositional dependence of optical parameters of Er3+ ions were studied,with the increases of B2O3 content in the glass.The parameters Ωt(t=2,4,6),FWHM,and temperature difference of ΔT=Tx-Tg increase monotonically,while the measured lifetime decreases.The optical properties of Er3+ in different glass hosts were compared.The results show that our Er3+-doped bismuth-based glass is much more beneficial for optical amplifier to realize broadband and high gain amplification.