Seven new cytotoxic xenicane-type diterpenoids, 9-deoxyxeniloide-E (1), 9-deoxy-7,8-epoxyxeniloide-E (2), xeniolide-G (3), 9-deoxyxenialactol-C (4), xenibecin (5), xeniolide-H (6), and xenitacin (7), were isolated from the methylene chloride solubles of the Formosan soft coral Xenia umbellata. The structures were elucidated by 1D and 2D NMR spectral analysis, and their cytotoxicity against selected cancer cells was measured in vitro.