This study aimed to observe the reflections of partial substitution of boron trioxide with samarium (III) oxide and its impact on structural, optical and physical behaviors through experimental and simulation methods. Accordingly, a thallium-borate glass group with a nominal composition of 30Tl(2)O(3)+10Li(2)O+(60-x) B2O3+xSm(2)O(3) system, where (x = 0, 0.2, 0.4 and 0.6 wt%), were prepared with the melt quenching method. The amorphous structure of thallium-borate glasses obtained using experimental XRD method. Further, UV and density analyses implemented to provide optical and material characteristics. A narrow beam geometry and experimental gamma-ray transmission method was used to measure the linear attenuation coefficient (LAC) at 0.081, 0.356, 0.662, 1.173 and 1.33 MeV to achieve the impact of this substitution on nuclear radiation shielding improvement. The radiation parameters were also measured using advanced Monte Carlo simulations by FLUKA general-purpose radiation transport code. It was found that both direct and indirect band gaps increase the value of eV as the Sm2O3 content increases from 0 to 0.6 wt-%, leading to more transparency. The most effective shielding properties was found for the BTLSm4 sample with x = 0.6 wt-%. Therefore, a Sm-borate glass containing 0.6 Sm2O3 was chosen as the best filter against radiation.