Sm2O3-doped SiO2-B2O3-Al2O3-BaO glasses were prepared by melting method in order to study the influence Of Sm2O3 on the crystallization behavior and luminescence properties. Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy were used to characterize the rare earth glasses and the crystalline phases after heat-treatment. The course of phase separation and devitrification of the glasses were also investigated. The results show that the thermal stability of the glasses decreases with the increase of content Of Sm2O3. The crystalline phase changed from SmAl2.07(B4O10)O-0.6 to SmBO3. Divalent Sm2+ ions were detected in the crystallization product after heat-treatment. The valence transformation from Sm3+ to Sm2+ in the crystal suggests the samarium atoms entering the barium sites. The charge carried in vacancy defect induced by the substitution led to the partial reduction process. The reduction Of Sm3+ ions was promoted by the increasing Of Sm2O3 content or the extending of heat-treated holding time in boroaluminosilicate glass. (C) 2008 Published by Elsevier Ltd.