In the course of studying on secondary metabolites from marine organisms, we have investigated the chemical constituents of the soft coral Sarcophyton ehrenbergi collected at San-Hsien-Tai, Taitong County, Taiwan. Chromatographic separation of the organic extracts has led to the isolation of nine new cembrane diterpenes 1¡V9, and a initial natural separation of known cembrane diterpene 10. The chemical structures of pure compounds were determined by spectral (NMR, MS, UV and IR) and physical data, as well as comparison with the spectroscopic data of related chemicals in literature. Moreover, the metabolites 1¡V10 were evaluated in vitro for their cytotoxicity against of A-549 (human lung epithelial carcinoma), HT-29 (human colon adenocarcinoma), and P-388 (mouse lymphocytic leukemia) cells, as well as anti-HCMV activity. Compounds 3, 6, 9, and 10 were shown to exhibit significant cytotoxicity activities against P-388 with ED50 values of 2.7, 3.6, 2.0, and 3.0 £gg/mL, respectively. Compound 1, 2, 3, and 7 exhibited inhibitory activity against anti-HCMV, with EC50 values of 60.0, 46.0, 5.0, and 45.0 £gg/mL.