Four new sesquiterpenes, lamellodysidines A and B, O,O-dimethyllingshuiolide A, and 11-epi-O,O-dimethyllingshuiolide A (1-4), were obtained from the marine sponge, Lamellodysidea herbacea, collected in Indonesia. Their planar structures were elucidated by analysis of spectroscopic data. The absolute configurations of the new compounds were determined by the calculated ECD spectra. Compound 1 has a unique carbon framework, and 2 is a new nitrogenous sesquiterpene.