Abstract: Three sesquiterpenoids were isolated from the dichloromethane extract of the roots of Stelleropsis tianschanica Pobed through a combination of various chromatographic approaches, including silica gel, Sephadex LH-20, reverse phase C₁₈ and so on. On the basis of spectroscopic data analysis, they were identified as (+)-guaia-l(10),ll-dien-9-one-5α-hydroxy (1), 4β,5βH-guai-9,7(11)-dien-12,8-olide-1α,8α-diol (2), 4α,5βHguai-9,7(11)-dien-12,8-olide-1α,8α-diol (3). The compound 1 is a new sesquiterpenoid, and the compound 3 was isolated for the first time from the genus Stelleropsis.