Water-based gel precipitation method was first applied to synthesize high purity nano CaZr0.9In0.10O3-delta powders suitable for fabricating dense ceramics at lower temperature. By using CaCO3, Zr(NO3)(4) and In (NO3)(3) as raw materials, PEG as dispersant, CaZr0.9In0.10O3-delta with an average particle size of about 40 nm was obtained at 850 degrees C, which was nearly 350 degrees C lower than that of traditional solid-state reaction method. Fully densified ceramics with an average grain size of 200-300 nm were obtained at 1350 degrees C, a temperature about 250 degrees C lower than that of traditional sintering techniques. Experimental results showed that the flexure stress, total, bulk and grain boundary protonic conductivities of the ceramics were more favorable than those of the ceramics fabricated at 1500 degrees C and 1600 degrees C from the powders synthesized by solid-state reaction method. (C) 2008 Elsevier B.V. All rights reserved.