Abstract:Ten compounds were isolated from the roots and stems of Cynanchum komarovii Al. Iljinski. They were identified as 7-demethoxylophorine (Ⅰ), epi-alnusenol (Ⅱ), β-sitosterol (Ⅲ), triacontanolic acid (Ⅳ), sucrose (Ⅴ), desoxytylophorinin N-oxide (Ⅵ), apocynine (Ⅶ), paeonol (Ⅷ), β-sitosteryl-β-D-glucopyranoside (Ⅸ) and glucose (Ⅹ) by means of UV, IR, NMR, MS spectral analyses and through chemical methods. These compounds were first reported in this plant. One of them, Ⅵ is a new alkaloid. The bioassay results showed that the compounds Ⅰ, Ⅵ and reaction product Ⅺ exhibited cytotoxic effects to P-388 leukemia cell in vitro. Ⅺ is also a new compound.