Abstract: The gas-solid phase reactions of TiN nanopowders both with and without impregnation pretreatment were studied. Effects of n-butanol and hydrochloric acid on the formation of rutile TiO₂ were analyzed. TiN nanopowders without impregnation are oxidized into anatase TiO₂ at 350~550℃. Whereas rutile TiO₂ are obtained from TiN nanopowders impregnated with mixed solution of n-butanol and hydrochloric acid in air at 380℃. The result of XRD and TEM images indicate that rutile TiO₂ are rod-like with 16nm in radial direction. It shows that hydrochloric acid acts as the fundamental substance for rutile TiO₂ from TiN nanopowders at low-temperature, while n-butanol mainly inhibits the agglomeration of TiO₂.