SnO2 nanorods were synthesized by flame spray pyrolysis. Their morphology and structure were characterized. The as-prepared SnO2 nanorods grow along the (001) direction with the length of 200～350 nm and diameter of 30～50 nm. The effects of Fe doping and Sn4+ concentration on their morphology and growth mechanism were investigated. In the high temperature and rapid reaction process the Fe3+ could permeate in SnO2 crystals and promote their growth along the (001) direction. The gas sensing performance tests showed that the SnO2 nanorods exhibited more excellent gas sensing properties than SnO2 nanoparticles with a sensitivity of (12～100)×10-6 (ψ) ethanol as well as response and recovery times of 9.5 and 6 s, respectively.