Abstract: In order to search for new compounds with higher anti-cancer activities and lower toxicities, 18 dehydrogenated carboncyclic analogs of norcantharidin, of which 17 are unknown compounds, were designed and synthesized. Preliminary screening results revealed that compound Ⅴ₆, Ⅵ₆ and Ⅵ₄ exhibited fairly apparent inhibitory activity against the growth of human-hepatoma cells, Bei-7402, in vitro. The inhibitory rate of Ⅵ₄ is 52%, almost the same as that of norcantharidin, in the concentration of 0.05 μmol/ml.