Abstract:Ten known alkaloids, sinoacutine (Ⅰ), 1-tetrahydropalmatine (Ⅱ), d-stepharine (Ⅲ), 1- stepholidine (Ⅳ), 1-corydalmine (Ⅴ), stephanine (Ⅵ), palmatine (Ⅶ), dehydrocorydalmine (Ⅷ), stepharanine (Ⅸ) and roemerine (Ⅹ) were isolated from the roots of Stephamia yunnanensis H. S. Lo. Their structures were determined from spectral data and chemical evidence.