METHODS AND RESULTS: A new seco-neolignan glycoside, seco-dehydrodiconiferyl alcohol-4-O-β-D-glucopyranoside, together with eight known compounds, were obtained from the EtOH extract of the root bark of Ailanthus altissima. Their structures were elucidated based on the spectroscopic data. CONCLUSIONS: Three neolignan glycosides including 7,9,9'-trihydroxy-3,3',5'-trimethoxy-8-O-4'-neolignan-4-O-β-D-glucopyranoside, sonchifolignan B and Citrusin B exhibited moderate in vitro inhibitory effect on tobacco mosaic virus replication with IC50 values 0.30, 0.35 and 0.26?mmol?L?1, respectively.