Diels-Alder reaction between furan and maleic anhydride resulted in 5,6-dehydro norcantharidin, then norcantharidin was obtained by reduction. The substituted-carboxylic acid was condensed with N-aminothiourea in presence of phosphorus oxychloride, yielding 2-amino-1,3,4-thiadiazole derivatives. Novel norcantharidin derivatives were synthesized with acylation, then intramolecular condensation using norcantharidin (or 5,6-dehydro norcantharidin) and 2-amino- 1,3,4-thiadiazole derivatives. All the target compounds were confirmed by IR, (1)HNMR, ESI-MS and were reported for the first time. Norcantharidin derivatives antiproliferative assay was tested by MTT method against A549 and PC-3 cell lines. The results showed that all the norcantharidin derivatives displayed moderate inhibitory activities.