Four new triterpene saponins, clematomandshurica saponins A-D (1-4), together with three known saponins (5-7) have been isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of their spectroscopic evidence and hydrolysis. Clematomandshurica saponins A and B showed significant inhibitory activity on cyclooxygenase-2 (IC50 = 2.66 and 2.58 microM, respectively).