On the basis of prophase studies in our research group,it was found that seco-pregnane C21 steroid compounds had strong resistance activity against tobacco mosaic virus (TMV),in order to further screen the better active compounds,study on the chemical compositions of Cynanchum atratum was carried out in this study.Ten compounds were isolated from chloroform fractions of the ethanol extract from C.atratum.According to the physicochemical properties and spectroscopic data,the compounds identified as glaucogenin-C 3-O-α-L-diginopyranosyl-(1→4)-β-D-thevetopyranoside（1）, glaucogenin-C 3-O-β-D-oleandropyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-α-L-cymaropyranoside（2）, glaucogenin-C 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→4)-β-D-oleandropyranoside（3）, glaucogenin-A 3-O-α-L-cymaropyranosyl-(1→4)-β-D-digitoxopyranosyl-(1→4)-β-D-oleandropyranoside（4）, glaucogenin-A 3-O-α-L-diginopyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-D-oleandropyranoside（5）, glaucogenin-A 3-O-α-L-cymaropyranosyl-(1→4)-α-L-cymaropyranosyl-(1→4)-β-D-oleandropyranoside（6）, glaucogenin-A 3-O-α-L-cymaropyranosyl-(1→4)-β-L-cymaropyranosyl-(1→4)-β-L-cymaropyranoside（7）, glaucogenin-A 3-O-α-L-cymaropyranosyl-(1→4)-β-D-cymaropyranosyl-(1→4)-β-L-cymaropyranoside（8）, antofine（9）, 2-O-β-D-fructofuranosyl-β-D-glucopyranoside（10）.The compounds 1-8，and 10 were isolated from this plant for the first time.The bioactivity of compounds 1-9 were evaluated by inoculating half leaf method from inactivation effect,protection effect and curative effect,and the results showed that compounds 1 and 9 had significant anti-TMV activity.