Abstract: The effects of fertilization rates of nitrogen on some physiological characteristics and quality of oriental tobacco were studied by pot and field experiments. The results showed that with the raise of N application rates, the contents of chlorophyll, free amino acid, and the activity of nitrate reductase of fresh leaves in each growth stage tended upwards, the contents of total nitrogen, nicotine, protein and potassium of cured leaves increased obviously, no significant chlorine content change was found. The content of reducing sugar was higher in the treatment of 30kgN/ha. The total amount of 33 kinds of aroma components of cured leaves was higher under the conditions of 15-30kgN/ha and the lowest without N application.