This paper describes a new preparation process of highly densified bodies of a γII-Li3.4Si0.4V0.6O4 solid solution, which is the best lithium ion conductor among those containing silicates, via sintering a xerogel powder derived from alkoxides. The xerogel powder consisting of spherical, amorphous aggregates was prepared by hydrolysis of alcoholic solutions of Si(OC2H5)4, VO(OC2H5)3 and LiOC2H5 at 70°C, followed by drying. The diameter was smaller than 0.1μm. The powder crystallized gradually into the βII-solid solution with poor crystallinity above 500°C, and a γII-solid solution appeared above 650°C. The highly densified bodies of the γII-solid solutions were obtained by sintering the compact of the xerogel powder at a relatively low temperature, 900°C. The sintered bodies consisted of only the γII phase and contained no other phases such as Li2SiO3 which forms as a result of Li2O evaporation during sintering. This method lowered the sintering temperature by 150°C compared with that for the conventional method. The ionic conductivities of the sintered bodies were determined by analysing their complex impedance diagrams in the frequency range of 5Hz-13MHz. The sintered bodies prepared by the conventional method were characterized by the presence of two distinct semicircles in the complex impedance diagram; one corresponds to AC response of the grain (bulk) and the other to that of the grain boundaries. However, the sintered bodies prepared by this method indicated only a single semicircle due to AC response of the grain. The total ionic conductivity of the sintered bodies, 3.4×10-5Scm-1 at 25°C rising to 4.7×10-3Scm-1 at 150°C, was about three times higher than that of the those prepared by the conventional method due to negligible grain boundary resistance.