In our ongoing research for secondary metabolites from the Formosan soft corals, six sesquiterpenoids namely GN76-9-1 (1), GN76-10-3 (2), GN76-12-6-10-1 (3), GN76-25-1 (4), GN76-25-5 (5), and GN76-30-5 (6) were isolated from Lemnalia flava (GN76). Among these secondary metabolites, compound 1 possessing a ylangene-type skeleton is a new natural product. Chromatographic separation of the extracts of the Formosan soft coral Efflatounaria tottoni yielded one known compound, GN79-11-3 (7), having an alcyonolide-type structure. In addition, two known germacrane-type sesquiterpenoids, GN82-11-4-2-15 (8) and GN82-16-5-6-25 (9), were isolated from the extracts of the Formosan soft coral Klyxum simplex (GN82). The structures of compounds 1 possessing a ylangene-type skeleton is a new natural product. Chromatographic separation of the extracts of the Formosan soft coral Efflatounaria tottoni yielded one known compound, GN79-11-3 (7), having an alcyonolide-type structure. In addition, two known germacrane-type sesquiterpenoids, GN82-11-4-2-15 (8) and GN82-16-5-6-25 (9), were isolated from the extracts of the Formosan soft coral Klyxum simplex (GN82). The structures of compounds 1-9 were elucidated by extensive spectral analyses. The anti-inflammatory and neuro-protective activities of these compounds were measured in vitro. Compound 2 showed more specific inhibition against the increase of the pro-inflammatory iNOS and COX-2 proteins of LPS-stimulated RAW264.7 macrophage cells. Compound 8 also reveals more specific neuro protective activity to human neuroblastoma cells SH-SY5Y.