Abstract: 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.