10mol% Gd2O3-doped CeO2 solid solutions (20GDC) have been synthesized via carbonate coprecipitation using ammonium bicarbonate (AHC) and urea as the precipitants. The precursors and the resultant oxide powders were characterized via chemical analysis, X-ray diffractometry (XRD), Brunauer-Emmett-Teller (BET) analysis, and high-resolution scanning electron microscopy (HRSEM). Sinterabilities of the 20GDC oxides in air were studied by constant-rate-of-heating (CRH) sintering and the conventional ramp-and-holding sintering methods. The precursor processed by both methods is hydroxyl carbonate but shows quite different particle morphologies in the two cases. Highly sinterable 20GDC oxides that can be densiried to >99% of the theoretical at 1050degreesC within 4 h have been obtained via the AHC method.