Layered titanate nanosheets were synthesized by hydrolyzing titanium tetraisopropoxide (TIPT) in hydrothermal solution using triethanolamine (TEOA), and dodecanediamine (DDA) as surfactant. The effects of synthesis conditions on the formation of layered titanate nanosheets were investigated. A layered structure of the titanate was produced under basic (pH12.8) conditions using NaOH or NH(4)OH aqueous solution. The flaky forms were observed only in reaction mixtures that included DDA, and the flaky forms had multilayer structure comprising several monolayer sheets. In addition, TEOA and DDA promote control of the crystalline structure of layered titanate. The surface acidity of layered titanate nanosheets was studied by coloration with color indicator reagents. The acidity of the sample corresponds to that of dilute hydrochloric acid. It is assumed that acid sites can be formed on the surface of titanate nanosheets by elimination of NH(4)(+) caused by calcination in air.