This experiment was conducted to investigate the effects of fertilization level, additional dressing time and form of nitrogen on the growth and formation of Alkaloid in flue-cured tobacco. The results are abstracted as follows. Length and width of harvested leaves, area of a leaf, leaf area per plant, number of harvested leaves, weight of a leaf, and leaf weight of a plant were larger in the $NO_3$-N plot than $NH_4$-N plot. Length, width and area of the middle leaves increased by additional dressing on 7 days before topping, but the dry weight Per unit leaf area of those was decreased. Leaf shape was broaden in additional dressing plots in comparison with 100% of basal dressing plot, but there is no difference among the additional dressing plots. And the smallest leaf shape index was shown at upper leaves in 100% of basal dressing Plot. Leaf weight of a Plaint was the highest in 12kg/10a Plot among $NO_3$-N form and in 12kg/10a plot among $NH_4$-N form. Total Alkaloid content was higher in $NH_4$-N plot between fertilization forms, and highest in 15kg/10a plot among fertilization levels and at the position of middle and upper leaves in the plot of 7 days before topping among additional dressing times.