Two new polyoxypregnane glycosides, haifengtenoside A (1) and haifengtenoside B (2), together with two known mucronatoside H (3) and hainaneosides A (4) were obtained from the stems of Marsdenia officinalis Tsiang et P.T.Li. (Asclepiadaceae). Their structures were elucidated as 12-O-cinnamoyl-20-O- acetyl(20S)-pregn-6-ene-3β,5α,8β,12β,14β,17β,20-heptanol 3-O-methyl-6-deoxy-β-D-allopyranosyl-(1→4)- β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranoside (1); 12-O-cinnamoyl-20-O-acetyl(20S)-pregn-6-ene-3β, 5α,8β,12β,14β,17β,20-heptanol 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D-allopyranosyl- (1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside(2); 12-O-cinnamoyl-20-O-acetyl(20S)-pregn- 6-ene-3β,5α,8β,12β,14β,17β,20-heptanol 3-O-β-D-thevetopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β- D-cymaropyranoside(3); 12-O-nicotinoylsarcostin 3-O-β-D-glucopyranosyl-(1→4)-3-O-methyl-6-deoxy-β-D- allopyranosyl-(1→4)-β-D-oleandropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-cymaropyranoside
(4), respectively, on the basis of spectroscopic and chemical means.

Key words: Marsdenia officinalis, haifengtenoside A, haifengtenoside B, mucronatoside H, hainaneoside A