The layer structured vanadate of Rb_3V_5O_<14> has been prepared using Rb_2CO_3 and V_2O_5 at 500℃. The ion exchange reactions of rubidium ion (Rb^+) in the interlayer space with sodium ion (Na^+), hydrogen ion (H^+) or lithium ion (Li^+) were studied in aqueous solutions. The sodium ion (Na^+) exchange product of Na_<2.00>H_<0.92>Rb_<0.08>V_5O_<14>・3.5H_2O was obtained. The host layers were retained on this ion exchange reaction. In contrast, any of ion exchange product of H^+ or Li^+ was not obtained. The reaction products were characterized by atomic absorption or flame analysis, TG-DTA and XRD.