Abstract: Eight coumarins were isolated from the root of ZOU-MA-QIN (Heracleum moellendorffii Hance Var. Paucivitatum). They were identified as isobergapten(Ⅰ), pimpinellin(Ⅱ), osthol(Ⅲ), bergapten (Ⅳ), isopimpinellin(Ⅴ), sphondin(Ⅵ), 4'-hydroxy-columbianetin(Ⅶ), by spectroscopic analysis (UV. IR.MS. ¹H NMR). (Ⅷ) is a new coumarin named moellendorffiline, C₂6H₂0O₁0,m. p. 244-246℃, its structure was determined by X-ray crystallographic analysis.The space group of the crystal is monoclinic P2₁/c, with four molecules in aUnit cell. The cell dimension are a=15.875, b=10.260, c=14. 602, β=107.24.Six coumarins (Ⅰ～Ⅵ) were isolated from the leaves and seeds of the same plant.