[en] The authors have been trying to clarify the origin of perpendicular magnetic anisotropy (K_{perpendicular}) of amorphous rare earth-transition metal ally films, by means of changing the kind of rare earths and their composition systematically for Fe or Co based binary systems. In this study, they used Gd, Dy, and Er as the rare earth elements, and investigated the temperature dependence of K_{perpendicular} and the saturation magnetization M_s, as well as the film magnetostriction