Objective: To study the major chemical constituents from the underground part of Isodon flavida. Method: Compounds were isolated and purified from ethyl acetate fraction of 70% acetone extract of the underground part of I. flavida using silica gel

sephadex LH-20

and MCI column chromatographic techniques. Their structures were determined by comparison of physicochemical properties and analysis of spectroscopic data. Result: Eleven compounds were obtained and identified as squalene (1)

stigmast-4-en-3-one (2)

stigmast-4-ene-3

6-dione (3)

8(17)

13-ent-labdadien-15→16-lactone-19-oic acid (4)

1-monoolein (5)

2α-hydroxyl ursolic acid (6)

maslinic acid (7)

2α

3α

23-trihydroxyursa-12

20(30)-dien-28-oic acid (8)

stigmasterol (9)

7α-hydroxy-sitosterol (10)

and β-sitosterol (11). Conclusion: All of these compounds except for 7 were isolated from the plant for the first time. This study will be helpful for the better understand of the chemical properties of the underground part of Isodon plants.