Objective: To study the chemical constituents of Yao medicine Pileostegia tomentella

and promote its further development and utilization. Method: Solvent extraction method

silica column chromatography and recrystallization method were used to isolate and purify the chemical constituents of 95% ethanol extract from this plant. The structures of the obtained compounds were identified by infrared spectroscopy

mass spectrometry

nuclear magnetic resonance spectroscopy and other modern spectroscopic methods. Result: From the data of spectral analysis

nine compounds were obtained and identified as: n-tetracosanoic acid (1)

taraxerol (2)

β-sitosterol (3)

3β-acetoxy ursolic acid (4)

stigmastane-3

6-dione (5)

7-hydroxy-8-methoxycoumarin (6)

skimmin (7)

7-hydroxycoumarin (8)

and protocatechoic acid (9).Among them

compounds (6)

(7) and (8) were coumarins. Conclusion: Compounds 1-9 were isolated from this plant for the first time. It showed that coumarins were widely contained in this plant.