Abstract: Three new oxoisoaporphine-type alkaloids were isolated from the ethanolic extract of the rhizoma of Menispermum dauricum DC. The structures of alkaloids Ⅰ, Ⅱ and Ⅲ were elucidated as 5,9-dimethoxy-7H-dibenzo (de, h) quinolin-7-one, named bianfugecine, 5,6-methylenedioxy-9-methoxy-7 H-dibenzo (de, h) quinolin-7-one, named bianfugedine, and 4,5,6,9-tetramethoxy-7H-dibenzo (de, h) quinolin-7-one, named bianfugenine, respectively. The present paper is the second report of the natural occurrence of this new type oxoisoaporphine alkaloids.