In this study, it was found that BaO-B₂O₃-SiO₂ glass powders with fine particle sizes and spherical shapes improved the sintering characteristics of nanosized BaTiO₃ powders. The mean sizes of the prepared glass powders and BaTiO₃ powders were 940 nm and 110 nm, respectively. The densities of BaTiO₃ pellets containing 0, 1, 3, and 5 mass% of a glass additive were 4.2, 5.2, 5.5 and 5.7 gcm^-3, respectively, at a sintering temperature of 900°C. The densities of BaTiO₃ pellets sintered at 900°C and containing 5 mass% of the glass additive were similar to that of the pellet sintered at 1280°C and containing no glass additive. Dielectric constants of pellets containing 5 mass% of the glass additive and of pellets containing no glass additive were 1599 and 469, respectively, at a sintering temperature of 900°C. Dielectric constants of pellets containing 1 mass% of the glass additive increased from 602 to 4109 when the sintering temperature was increased from 800 to 1200°C.