It was shown in many literature sources that ionic conductivity of the LiTi2(PO4)(3) compound was increased by several orders substituting Ti4+ ion by trivalent ions. In the case of substituting by La3+ there was no success to synthesize single phase material. The two phases were obtained and conductivity increased considerably. In the present work the substitution Ti4+ -> La3+ + Li+ in the LiTi2(PO4)(3) system was studied by XRD, SEM, XPS, WDX, and impedance spectroscopy. The powder was prepared by solid state reaction with relative mixture of initial materials to obtain Li1+xLaxTi2-x(PO4)(3) with x=0.3, but the impurity of LaPO4 was detected by XRD. The ceramic samples were sintered with different sintering duration to check the influence of sintering on composition and electrical propel-ties. (c) 2007 Elsevier B.V. All rights reserved.