Abstract: To discover new cytotoxic constituents from the traditional tibetan medicine-“Zuomaoxing”(roots of Caragana jubata (pall) Poir.),the isolation and purification of a methanolic extract was performed with medium-pressure column chromatography and preparative HPLC. Eight pure compounds were obtained and their structures were elucidated as 6,7,3′-trihydroxy-4′-methoxyisoflavone (1), 3,7-dihydroxy-4′-methoxyflavonone (2),3-methoxy-4,9-dihydroxy pterocarpan (3),7,3′-dihydroxy-5′-methoxyisoflavone (4),6,7-dihydroxy-4′-methoxyisoflavone (5),3,9-dimethoxy-8-hydroxy pterocarpan (6),3,9-dimethoxy-4-hydroxy pterocarpan (7) and 3-methoxy-4-hydroxy maackiain (8) based on detailed spectral analysis.All compounds were isolated from the title plant for the first time.In vitro cytotoxic activity of compounds 1—8 were evaluated using MTT method,and the results showed that all compounds exhibited cytotoxic activity against HepG2 and Hep3B cell lines with IC50 values ranging from 22.5 to 104.7 μg/mL.