Glycyrrhetinic acid (GA) is a natural product with certain antitumor activity. In order to enhance the cytotoxicity, a total of eighteen derivatives of GA were designed and synthesized. Their cytotoxicity against MDA-MB-231cells (human breast cancer cells) and HeLa cells (human cervical cancer cells), were evaluated by the MTT method (3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide).