Three new 3,4- seco-lanostanes, kadsuracoccinic acids A-C ( 1- 3), were isolated from the medicinal plant Kadsura coccinea, in addition to the known compounds kadsuric acid ( 4) and micranoic acid A ( 5). The structures of 1- 3 were elucidated by analysis of their 2D-NMR spectroscopic data. Furthermore, the relative conformation of 1 was confirmed by an X-ray crystallographic study. This is the first report of a 3,4- seco-lanostane-type triterpene with a 17(20)-ene functional group. Treatment of cultured individual Xenopus laevis cells with 1 at the blastular stage arrested cleavage of these cells with an IC 50 of 0.32 microg/mL.