To isolate and identify the chemical constituents from the roots of Peucedantu praeruptorum.The constituents were isolated by column chromatography on silica gel and ODS, and identified by NMR, MS spectroscopic methods.Eight compounds, (-) sclerodin (1), palmitic acid (2), (+)-praeruptorin E (3), bergapten (4), imperatorin (5), 2,6-dimethyl quinoline (6), tetracosanoic acid (7), and daucosterol (8), were isolated and identified.Compounds 1,5-7 were isolated from this plant for the first time.