The present invention relates to optical glass and an optical element composed of the optical glass, and particularly relates to optical glass which has optical constants of medium refractive index and low dispersion and is suitable for press molding process and to an optical element composed of the optical glass. The optical glass includes, based on the total weight of the optical glass: not less than 35 weight percent and less than 45 weight percent of P2O5; not less than 0.5 weight percent and less than 10 weight percent of B2O3; 0 to 16 weight percent of Al2O3; 0 to 2.5 weight percent of SiO2; 0 to 26 weight percent of BaO; 0 to 20 weight percent of SrO; 23 to 49 weight percent of ZnO; more than 6 weight percent and not more than 20 weight percent of CaO; 0 to 16 weight percent of MgO; not less than 0 weight percent and less than 1 weight percent of Li2O; 3 to 19 weight percent of Na2O; and 0 to 20 weight percent of K2O, where the total weight of BaO, SrO, ZnO, CaO, and MgO is below 55 weight percent and the total weight of Li2O, Na2O is below 24 weight percent.