Abstract: <FONT face=Verdana>8YSZ （amount-of-substance of Y<SUB>2</SUB>O<SUB>3 </SUB>in ZrO<SUB>2</SUB> is 8%）nano-powder was prepared by sol-gel method in citric acid medium.Effect of pre-sintered temperature on powder size and effect of sintered temperature on powder density and conductivity were studied.Results indicated that the powder size increased while pre-sintered temperature was raised;its size was 5 nm at 500 ℃;density and conductivity both increased when sintered temperature was raised;density continued to increase but conductivity remained unchanged when sintered temperature raised from 1 300 ℃ to 1 400 ℃;sintering can be promoted when the sample was doped by ZnO;conductivity decreased when ZnO content was more than 2%(amount-of-substance fraction).</FONT>