Abstract: The conditions for determining total nitrogen in tobacco with ALLIANCE-SINGLE analyzer were optimized. 0.1-0.2g tobacco powder was digested with 0.40g CuSO₄, 6.00g K₂SO₄, and 7.00mL concentrated H₂SO₄ under 180℃ for one hour and then 380℃ for 1-1.5 hours, cooled to room temperature, diluted with ionfree water, added with sodium dicholoroisocyanourea as color-developing agent, 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.