Objective To investigate the secondary metabolites of the South China Sea sponge Acanthella cavernosa. Methods The acetone extract of A. cavernosa was purified by repeated column chromatography on silica gel, sephadex LH-20, and high-performance liquid chromatography (HPLC). Structures of the extract were determined by spectroscopic analysis and comparison with previously reported data. Results and Conclusion A total of 7 compounds were isolated and their structures were identified as kalihinene X-Z (1 - 3), (R)-3,5-diethyl-5-((S,E)-2-ethylhex-3-en-1-yl)furan-2(5H)-one (4), methyl(2Z,6R,8S)-4,6-diethyl-3,6-epoxy-8-methyldodeca-2,4-dienoate (5), methyl(2Z,6R,8R,9E)-3,6-epoxy-4,6,8-triethyl-2,4,9-dodecatrienoate (6), and methyl(2Z,6R,8S)-3,6-epoxy-4,6,8-triethyldodeca-2,4-dienoate (7); and compounds 4 - 7 were identified from the genus Acanthalla for the first time.