Abstract:Phellodendron amurense Rupr. (Rutaceae) is a deciduous tree commonly called the Amur cork tree. It is a kind of endemic species in China. The bark of P.amurense has been widely used as a traditional medicine in China. The resources of P.amurense have been excessively exploited due to its important biologically-active components. In this paper, HPLC was used to determine the contents of ajrtohrrizine, palmatine and berberine. The impact of different parts, seasons and ages on the alkaloid distribution was analyzed. The results showed that: the relative ajrtohrrizine levels were: root bark>trunk bark>perennial branch bark>annual branches>leaves. the palmatine contents were: trunk bark>perennial branch bark>root bark>annual branches>leaves. The berberine levels in different parts were: root bark>trunk bark>perennial branch bark>annual branches>leaves. The jatrorrhizine contents in root bark and trunk bark gradually increased along with the season passed, i.e. autumn>summer>spring. The jatrorrhizine levels in perennial branch bark, annual branches and leaves were autumn>spring>summer. The palmatine in every plant parts increased along the season, i.e. autumn>summer>spring. The berberine was the highest value, the contents in root bark, trunk bark and perennial branch bark increased along the season changed firstly, then reduced in autumn, i.e. summer>autumn>spring. The berberine content in annual branches was initially reduced in summer, then increased in autumn.