We have studied the correlation between liquid fragility and the inward diffusion (from surface toward interior) of alkaline earth ions in the SiO2-Na2O-Fe2O3-RO (R = Mg, Ca, Sr, Ba) glass series. The inward diffusion is caused by reduction of Fe3+ to Fe2+ under a flow of H-2/N-2 (1/99 v/v) gas at temperatures around the glass transition temperature (T-g), The consequence of such diffusion is the formation of a silica-rich nanolayer. During the reduction process, the extent of diffusion (depth) decreases in the sequence Mg2+, Ca2+, Sr2+, and Ba2+, whereas the fragility increases in the same sequence. It is found that the ratio of the activation energy of the inward diffusion E-d near T-g to the activation energy for viscous flow E-eta at T-g increases with increasing fragility of the liquid. The inward cationic diffusion can be enhanced by lowering the fragility of glass systems via varying the chemical composition.