We give an interpretation for the observed systematic trend of magnetic circular dichroism (MCD) in L 2,3 photoabsorption of rare-earth (RE) atoms from Ce to Tm in ferro- or ferrimagnetic RE 2 Co 17 assuming the 2 p →5 d electric dipole transition. We assume that the 4 f state of trivalent RE ions is in the polarized Hund-ground-state. We then take into account the spin and orbital magnetic moments induced in the RE 5 d state through the intraatomic 4 f -5 d exchange interaction approximated by a molecular field with assuming a band width of several eV and one tenth filling of the 5 d band. The integrated MCD intensity calculated with a naive one-electron picture is shown to correspond well to the observed trend. The 5 d orbital moment estimated both from the present model and from a MCD sum rule applied to the experiment is of the order of ∼ 0.1 µ B , which is comparable to the 5 d spin moment.