Sm3+-doped heavy-metal-gallate glasses are fabricated by the high-temperature solid melting method. The Judd-Ofelt parameters Ω2, Ω4, and Ω6 are 3.00×10-20, 5.19×10-20, and 1.69×10-20 cm2, respectively. Then the radiative transition probabilities, fluorescence branching ratios, and radiative lifetime are calculated. Under the excitation of 488 nm bluish-green light, the fluorescence bands centered at 534, 564, 601, 648, and 710 nm are observed, corresponding to the transitions of 4F3/2→6H5/2, 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2, and 4G5/2→6H11/2, respectively. The emission bands with the peaks at 960, 1038, and 1185 nm are recorded in near infrared region, which are attributed to the transitions of 4G5/2→6F5/2, 4G5/2→6F7/2, and 4G5/2→6F9/2, respectively. The observed 4G5/2→6F9/2 infrared emission lies in the low-loss window of telecommunication system, and the maximum value of stimulated emission cross-section for this transition is 6.09×10-23 cm2.