To provide optical glass which corrects the chromatic aberration of a glass lens with a high precision because it has high anomalous dispersion, has a high refractive index, a low dispersion (high Abbe's number), and an abrasion equal to or lower than that of a conventional one, and thereby is easily subjected to polishing, and to provide an optical element and a preform.

The optical glass includes at least one selected from the group comprising P, Al, alkaline earth metals, Zn, Y, La, Gd, Yb and Lu as a cationic component, and F and O as anionic components, and has a partial dispersion ratio (θg, F) of ≥0.535 and a refractive index (nd) of ≥1.44.