The layered titanate CsxTi2-x/4O4has been synthesized in the range of 0.68 ≤ × ≤ 0.88 at 700°C. Lithium has been intercalated into the titanate Cs0.68Ti1.83O4(x = 0.68 in CsxTi2-x/4O4) chemically and electrochemically. The increase of the electrical conductivity on the intercalation is estimated at a factor of 105at room temperature. The saturated intercalation compound of Li0.48Cs0.68Ti1.83O4shows the broad optical absorption spectrum around 1050 nm due to the intervalence transition in the same manner as mixed-valence oxide such as HXWO3. The titanate exhibits electrochromism on the intercalation-deintercalation of lithium.