Abstract: Nanosized particles of Ce_0.8Gd_0.2O_1.9（GDC） electrolyte materials for low-temperature solid oxide fuel cells were prepared by a so called sol-combustion technique using citric acid as the chelating agent.The effects of different sintering temperature were investigated on the evolution of crystalline phase,particle size,and lattice parameters of the resulted GDC.Ultra-fine GDC powders of around 30nm in diameter were successfully prepared by the sol-combustion technique.The powders showed a high sintering activity,and GDC ceramic could reach 95% of the theoretical at a sintering temperature of 1500℃.Electrochemistry measurements showed that the GDC ceramics had relatively high oxygen ionic conductivity in low-temperature range.