Abstract: The conditions for determining total nitrogen in tobacco with API analyzer were optimized.0.1-0.2 g tobacco powder was digested with 0.4 g CuSO₄,3 g  K₂SO₄,and 6.0 mL concentrated H₂SO₄ under 150 ℃ for one hour and then 380  ℃ for3 h,cooled to room temperature，diluted with ionfree water,and finally analyzed with the instrument.The results determined with the continuous flow analytical method were comparable with those of the standard one.The conclusion was that total nitrogen in tobacco could be determined with the continuous flow analytical method．

Key words: continuous flow analytical method, total nitrogen, tobacco