Nitrogen nutrition is one of the important environmental factors that affect plant growth and secondary metabolism. It's a key and active element in plant nutrition. Corktree (Phellodendron amurense) is a valuable resource for both lignum and Chinese traditional medicine. It is listed at the second place as one of national protected plants in China. Berberine, jatrorrhizine and palmatine are three main bioactive alkaloids in corktree. In this paper, effect of nitrogen forms on alkaloid contents was investig...