8%(mole fraction) yttria-stabilized zirconia electrolyte thin wall tubes were prepared by improved slip casting method. The length and wall thickness of the tubes are 266 mm and 0.4～0.9 mm, respectively and the relative density is 96.7%. The microstructure and electrical properties of samples sintered at different temperatures were studied using SEM and ac impedance spectroscopy. The effect of sintered density, grain and grain boundary on the electrical properties of the samples was analyzed. The research results show that the density of the samples increases gradually with increasing sintering temperatures. The microstructure of samples strongly influences its electrical properties, and the electrical properties of samples enhance with the increase of sintered density. The ionic conductivity of grain and grain boundary is increased as the sintering temperature increases. Better sinterability of the samples was obtained at the sintering temperature of 1650 ℃. The maximum open circuit voltage and short circuit current for single cell is 0.946 V and 1.84 A, respectively. The maximum output power of single cell is 0.46 W at the temperature of 850 ℃.