Four new triterpenoid glycosides were isolated from the root bark of Mussaenda macrophylla. Their structures were determined as 3-O-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-16alpha- hydrox y-23-deoxyprotobassic acid (1), 28-O-beta-D-glucopyranosyl-16alpha-hydroxy-23-deoxyprotobassic+ ++ acid (2), 3-O-beta-D-glucopyranosyl-28-O-alpha-L-rhamnopyranosyl-16alpha- hydrox yprotobassic acid (3), and 3-O-¿[beta-D-glucopyranosyl-(1-->6)]-O-alpha-L-rhamnopyranosyl-(1-->2 )-O-beta-D-glucopyranosyl-(1-->2)¿-O-beta-D-glucopyranosyl-(1-->3)-O- beta-D-glucopyranosyl-cycloarta-22,24-dien-27-oic acid (mussaendoside W, 4). Four known triterpenoids [3-O-acetyloleanolic acid (5), 3-O-acetyldaturadiol (6), rotundic acid (7), and 16alpha-hydroxyprotobassic acid (8)] were also isolated. The structures of 1-4 were determined by several spectroscopic techniques including 2D NMR methods. Compounds 1-6 showed inhibitory activity against a periodontopathic bacterium, Porphyromonas gingivalis, but were inactive against the cariogenic organism, Streptococcus mutans.