The layer structured titanoniobate CsTiNbO5 has been prepared in a solid state reaction using Cs2CO3, anatase type TiO2 and Nb2O5 at 1073 K. Ion exchange reactions of Cs+ in the interlayer space were studied in aqueous solutions. The host layers of the titanoniobate were maintained on the ion exchange reactions and the resulting products were found to contain interlayer water. The interlayer water in the lithium ion exchange product was removed by heating at 453 K in a vacuum. The resulting titanoniobate Cs0.10Li0.60H0.30TiNbO5 was evaluated for its use as the cathode in a rechargeable lithium battery. The cathode exhibited discharge and charge capacities of 130 and 99 mAhg-1 for the first cycle in the voltage range of 1.5 - 4.2 V. The amounts of Li+ intercalated and deintercalated were 1.16 and 0.88 of the formula unit, respectively.