Abstract: Drevogenin Ⅰ, Ⅱ, two new aglycones, were isolated from Dregea sinensis var. corrugata(Asclepiadaceae). The mass spectrum suggests the presence of two isovaleryl groups.Alkaline hydrolysis of compound Ⅰ with 5% methanolic potassium hydroxide yielded deacyldrevogenin Ⅰa and isovaleric acid.The acid was esterified with methanol--surfuric acid to afford methyl-isovalerate. By GLC comparison with authentic sample,relative retention time was the same,¹H-NMR shift (δppm) and coupling constant were the same, too. On the basis of spectroscopic analysis and chemical reactions, given above the structure of aglyeone Ⅰ was established as C/D cis 5α-H,3β,8β,14β,17β tetrahydroxy- 12β-O-isovaleryl-20-O-isovalerylpregnane. MS moleculer weight 552 and elementary analysis were compatible with C₃₁H₃₂O₈.The structure of aglycone Ⅱ was established as C/D cis 5α-H,3β,14β,17β trihydroxy-12β-O-acetyl-20-O-benzoyl-pregnane,The mass spectrum suggests the presence of benzoyl and acetylgroups. Alkaline hydrolysis of Ⅱ with 5% methanolic potassium hydroxide yielded tomentogenin Ⅱa and an acetic acid. Partial alkaline hydrolysis of Ⅱ with 8% K₂CO₃--MeOH--H₂O afforbed a 12-hydroxy-20-O-benzoyl-pregnane.