Phytochemical investigation on the stems of Kadsuru coccinea led to the isolation of 8 new triterpenoids, kadcoccilactones K-R (1-8), and 10 known analogues. Their Structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1-3 characterized with an aromatic ring E in their molecules are rarely naturally Occurred kadlongilactone derivatives. Moreover, all compounds were evaluated for their inhibitory activity against K562, Bel-7402, and A549 human tumor cells. Compounds 9 and 10 exhibited potent cytotoxicity against K562, Bel-7402, and A549 cell lines with IC50 Values less than 0.1, 0.1, and 1.0 mu m, respectively. (C) 2008 Elsevier Ltd. All rights reserved.