Abstract: Objective To study the chemical constituents in the stems of Marsdenia tenacissima. Methods Ten compounds were isolated and purified by silica gel column chromatography and Sephadex LH-20. The chemical structures of the compounds were elucidated by their physicochemical properties and spectral data, such as MS, IR, UV, ~1H-NMR, and ~(13)C-NMR. Results The compounds were obtained from the water extract of the plant. They were poke-weed cerebroside ( I ), methyl β-D-theveropyranosyl-(l→4)-β-D-cymaropyranoside (Ⅱ), 11α, 12β-acetonide-tenacigenin B (Ⅲ), conduritol A (Ⅳ), l-(4-hy-droxy-3-methoxyphenyl)-2-{ 2-methoxy-4-[l-(E)-propen-3-ol]-phenoxy}-propan-l, 3-diol ( V ), D-galacti-tol (Ⅵ), scopoletin (Ⅶ), marsectobiose (Ⅷ), daucosterol (Ⅸ), and amber acid (X). Conclusion Compounds I and V are isolated from the plants of Marsdenia R. Br. for the first time; Compounds Ⅱ, Ⅵ-Ⅶ, and X are isolated from the title plant for the first time.