A high-refractivity high-dispersion optical glass for producing an optical element, which requires no machining, such as polishing or lapping, of an optical-function surface after precision press molding, containing B2O3, SiO2, La2O3, Gd2O3, ZnO, Li2O, ZrO2 and Ta2O5 as essential components, containing 0 to 1 mol % of Sb2O3 as an optional component, substantially containing none of PbO and Lu2O3, having a glass transition temperature of 630° C. or lower, and (1) having a refractive index nd and an Abbe's number nud which satisfy all of the following relational expressions, 1.80<nd<=1.90, 35<nud<=50, and nd>=2.025-(0.005xnud) or (2) having an nd of greater than 1.85 and a nud of greater than 35.