Provided is an optical glass for precision press-molding is free from degradations in product quality caused by a surface altered layer such as fogging, browning, etc., and a precision press-molding preform and an optical element provided are formed of the above glass. The optical glass is a glass which contains B.sub.2O.sub.3, La.sub.2O.sub.3 and ZnO and is used as a glass material for precision press-molding, and contains, by mol %, 20 to 60% of B.sub.2O.sub.3, 0 to 20% of SiO.sub.2, 22 to 42% of ZnO, 5 to 24% of La.sub.2O.sub.3, 0 to 20% of Gd.sub.2O.sub.3, provided that the total content of La.sub.2O.sub.3 and Gd.sub.2O.sub.3 is 10 to 24%, 0 to 10% of ZrO.sub.2, 0 to 10% of Ta.sub.2O.sub.5, 0 to 10% of WO.sub.3, 0 to 10% of Nb.sub.2O.sub.5, 0 to 10% of TiO.sub.2, 0 to 10% of Bi.sub.2O.sub.3, 0 to 10% of GeO.sub.2, 0 to 10% of Ga.sub.2O.sub.3, 0 to 10% of Al.sub.2O.sub.3, 0 to 10% of BaO, 0 to 10% of Y.sub.2O.sub.3 and 0 to 10% of Yb.sub.2O.sub.3, has an Abbe's number (.nu.d) of 40 or more and is substantially free of lithium.