The spectroscopic properties of Tm3+ ions in PbO-Bi2O3-Ga2O3-GeO2 glasses were investigated through the absorption, emission, and lifetime measurements. The JO intensity parameters, the spontaneous emission probability, the fluorescence branching ratio, and the radiative lifetime were calculated using the Judd-Ofelt theory. From the measured 1470nm band emission spectra, we found the FWHM was ～122nm and the peak stimulated emission cross-section was ～2.2×10-21cm2, but the measured lifetimes decreased with the Tm3+ ion concentration increasing and the increase of cross relaxation rates was a function of the square of the Tm3+ ion concentration. As a result, PbO-Bi2O3-Ga2O3-GeO2 glasses were still thought to be a promising host material for potential S-band optical fiber amplifiers.