An optical glass having properties of a high refractive index and low dispersion and having both a low sag temperature Ts and a low liquidus temperature L.T., is provided. The optical glass comprises, by % by weight, 25 to 42% of B2O3, 14 to 30% of La2O3, 2 to 13% of Y2O3, 2 to 20 of SiO2, greater than 2% and 9% or less of Li2O, 0.5 to 20% of CaO, 2 to 20% of ZnO, 0 to 8% of Gd2O3, 0 to 8% of ZrO2, Gd2O3+ZrO2 being 0.5 to 12%, the total content thereof being at least 90%, and optionally contains 0 to 5% of Na2O, 0 to 5% of K2O, 0 to 5% of MgO, 0 to 5% of SrO, 0 to 10% of SrO, 0 to 10% of BaO, 0 to 5% of Ta2O, 0 to 5% of Al2O3, 0 to 5% of Yb2O3, 0 to 5% of Nb2O5, 0 to 2% of As2O3 and 0 to 2% of Sb2O3.