A new nortriterpene, rhombenone (1) was isolated from the leaves ofHedera rhombea Bean (Araliaceae). The structure of this compound was established as 27-demethyl-20(S)-dammar-23-ene-6alpha,20-diol-3,25-dione on the basis of spectral analysis including HMQC and HMBC techniques. Rhombenone (1) was the first 27-demethyl nortriterpene of dammarance type isolated from natural sources.