Abstract: The roots of S. lappo C. B. Clarke afforded in addition to thirteen sesquiterpenoid con-stituents (1 and 3~ 14) reported a new sesquiterpene aldehyde (2). The structure of the new com-pound was established by spectral method. Moreover, among the thirteen known sesquiterpenoid constituents, Compound 4, 12 and 14 have been obtained from this plant source for the first time.

Key words: Saussurea lappa