Two new alkaloids (1 and 2), one new phenolic glycoside (3), and five known structures (4–8) were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidence and hydrolysis products. All isolates were evaluated for inhibitory activity against LPS-induced nitric oxide (NO) production in RAW 246.7 macrophages. Feruloyl and isoferuloyl derivates showed moderate inhibitory effects with the inhibition ratios (%) from 29.3 to 38.7 at 50 μM, whereas 3-carboxy-indole derivates showed potent inhibitory activities with IC50 from 7.7 to 12.4 μM. © 2016 Phytochemical Society of Europe