The present invention provides an antibacterial glass composition exhibiting high antibacterial performance with sufficiently sustaining antibacterial performance by adding a small amount of the antibacterial component, and an antibacterial polymer composition using the antibacterial glass composition. The present invention provides an antibacterial glass composition containing 0.1 to 5.0% by weight of Ag₂O in a glass composition containing 30 to 60 mol % of P₂O₅, 1 to 15 mol % of one or more compounds selected from the group consisting of K₂O, Na₂O and Li₂O, 35 to 55 mol % of one or more compounds selected from the group consisting of MgO, CaO and ZnO, and 0.01 to 3 mol % of one or more compounds selected from the group consisting of La₂O₃ and Y₂O₃.