Thin film of a lithium ionic conductor, LiTi2(PO4)(3) (LTP), was prepared by sol-gel method from an alkoxide solution. Heating temperature of the spin-coated film between 600 and 800 degreesC resulted in single-phase UP films. The film heated at 800 degreesC showed a reticulation texture with a thickness of 300 nm. It showed a high lithium ionic conductivity 4.4 x 10(-6) S/cm, although it has a large porosity due to the texture. High sintering capability of the sol-gel film was regarded to reduce a grain boundary resistance in LTP substance, resulting in the high conductivity. (C) 2002 Elsevier Science B.V. All rights reserved.