Abstract: Two new prenylated flavonoids, flemiphilippinin C(Ⅰ) and flemiphilippinin D (Ⅱ) have been isolated from the root of Flemingia philippinensis (Merr. et Rolfe)Li along with four known compounds. The structure of Ⅰ and Ⅱ were elucidated as 7-(4′-hydroxy-3′-methoxyphenyl)-5-hydroxy-2, 2-dimethyl-10-prenyl-2H, 6H-benzo-1, 2-b: 5, 4-b′ dipyran-6-one and 5, 7, 2′, 4′-tetrahydroxy-6, 8- diprenylflavanone respectively, on the basis of chemical and spectroscopic data, The four known compounds were identified as 5, 7, 3′, 4′-tetrahydroxy-6, 8-diprenylisoflavone (Ⅲ), flemichin D (Ⅳ), β-sitosterol (Ⅵ) and lupeol (Ⅶ). and a mixture of n C₂₂～C₃₀ aliphatic acid (Ⅴ). Compounds Ⅲ and Ⅳ showed significant cytotoxic activities against P₃₈₈ cell cultures.