There is an increasing interest in exploring Artemisinin and its derivatives, clinically used antimalarial drugs, as novel anticancer agents.This presentation will focus on recent studies accomplished in our laboratory, in relation to their antitumor efficacy and underlying mechanisms of action in in vitro and in vivo models of human hepatoma and ovarian cancer.The in vitro cytotoxicities ofartemisinin and its derivatives were compared in human hepatoma cells (HepG2, Huh-7, BEL-7404, and Hep3B), ovarian cancer cells (A2780 and OVCAR-3), as well as normal human liver (7702) and ovarian surface epithelial (IOSE144) cells.Based on their activity and specificity, artemisinin and dihydroartemisinin were further investigated for their in vitro and in vivo antitumor effects and their effects on the protein expression of genes associated with cell proliferation and apoptosis.Dihydroartemisinin exerted the greatest cytotoxicity to hepatoma and ovarian cancer cells but significantly lower cytotoxicity to normal cells.