The effects of Na2O contents on spectroscopic properties of Er3+-doped Na2O-Al2O3-SiO2 glasses were studied in this paper. The Ωt parameters, radiative transition probability, and radiative lifetime of the Er3+-doped sodium aluminosilicate glasses were calculated by the Judd-Ofelt (J-O) theory and absorption spectra. Then the relationship between Ωt parameters and Na2O contents, and the effect of Na2O contents on absorrption cross section, and the spontaneous emission probability of the 4I13/2 level of Er3+, and the full width at half maximum(FWHM) of 1.53 μm were analysed.