Aim To study the chemical constituents from the roots and rhizomes of Clematis hexapetala Pall.. Methods The components were isolated by means of solvent extraction, repeated chromatography with silica gel, sephadex LH-20 and prep-HPLC. The structures were determined by spectrum analysis. Results Twelve flavonoids were isolated and their structures were identified as 3, 5, 6, 7, 8, 3＇, 4＇-heptamethoxyflavone （1）, nobiletin （2）, liquiritigenin （3）, hesperetin （4）, naringenin （5）, liquiritigen-7-O-β-D-glucopyranoside （6）, 5,7, 4＇ -trihydroxy-3＇- methoxyflavanone -7-O-α-L-rhamnopyranosyl （ 1→6 ） -β-D-glucopyranoside （7）, 6-hydroxybiochain A （ 8）, formononetin （9）, daidzein （10）, genistein （11）, and tectoridin （12）. Conclusion All the said compounds were isolated from the plant for the first time.
