Abstract: A new constituent,aristolochic acid BII methyl ester(5), was isolated from Aristolochia manshuriensis Kon. Its structure was elucidated as 3,4- dimethoxy-10- nitrophenanthrenic-1-acid methyl ester. Aristolochic acid Ⅰ(6),Ⅱ(8),Ⅲa(12),Ⅳ(9),Ⅳa(11),p-hydroxycinnalnicacid(10),-sitosterol(1), stigmastane- 3,6-dione(2),6-hydroxy- stigmas-4-en-3-one),daucosterol(7) and 1-octacosanoyl glyceride(4) were also isolated from this plant.