Abstract: Fe(Ⅲ)-doped ultrathin tungsten oxide (Fe-W₁₈O₄₉) nanowires were prepared with the simple solvent-thermal method to optimize the acetone-sensing performance of tungsten oxide acetone sensor materials for reason of the low response, poor selectivity and high detection temperature of pure tungsten oxide. The results showed that Fe(Ⅲ) doping not only inhibited the transformation of W₁₈O₄₉ crystal phase to WO₃ crystal phase but also optimized its gas-sensing performance. The W₁₈O₄₉ nanowires with doping ratio (n(Fe)/n(W)) of 0.10 demonstrated the best performance. This material showed a sensitivity of 11.4 for acetone with a volume fraction of 5×10^-5 at the optimum operating temperature of 220 ℃, with the response/recovery time of 14/16 s and good selectivity.