Abstract: Eight alkaloids have been isolated from the roots of Stephanie officinarurn Lo et Yang, which is a novel species growing in Gengma district of Yunnan province. The structures of these compounds were identified as isocorydine (Ⅰ), 1-tetrahydropalmatine (Ⅱ), sinoacutine (Ⅲ), crebanine (Ⅳ), isoboldine (Ⅴ), corytuberine (Ⅵ), palmatine (Ⅶ) and l-N-β-methyltetrahydropalmatine nitrate (Ⅷ) by spectral and chemical methods. One of them, compound Ⅷ is a new natural quaternary alkaloid. It is the first time that we find compound Ⅷ occurring in nitrate form in the plant. Isocorydine is a main alkaloid with 1.24% yield.