Antimony-doped tin dioxide is an excellent catalyst, which has good electrical conductivity and high temperature stability. The sol-gel method is used to prepare ATO nanopowders, and their structure characterization and performance analysis are also conducted. Stable tin and antimony citrate complexes solution is obtained from the starting materials metal tin and antimony trioxide. The solution undergoes sol-gel transformtion when acetonitrile is added dropwise. Antimony doped tin oxide nanoparticles are obtained with the washed gel heat-treated at different temperatures. The antimony doped tin oxide nanoparticles exhibit shrinking crystallite size, increasing specific surface area and tin oxide lattice parameters changing with the rise of antimony doping content. The crystalline size increases, while speciflc surface area decreases with the increase of annealing temperature. The particle crystallinity shows a decrease tendency for the high antimony doping level with increasing temperatures.