Background: Both alcohol and aqueous extracts of Sauromatum giganteum(Engl.) Cusimano and Hett, the driedroot tuber of which is named Baifuzi in Chinese, have been used for folklore treatment of cancer in Northeastof China. However, little is known about which is most suitable to the cancer therapy. Materials and Methods:Serum pharmacology and MTT assays were adopted to detect the effects of ethanol and aqueous extracts ofSauromatum giganteum(Engl.) Cusimano and Hett , prepared by heat reflux methods, on proliferation of differentcancer cells. Results: Cancer cells treated with medium supplemented with 10%, 20%, 40% serum(v/v) containingethanol extract had a decline in viability, with inhibition rates of 7.69%, 21.8%, 41.9% in MCF-7 cells, 42.8%,48.1%, 51.8% in SGC-7901 cells, 44.1%, 49.2%, 53.7% in SMMC-7721 cells, 6.8%, 15.2%, 39.8% in HepG2cells, 7.57%, 16.3%, 36.2% in HeLa cells, 6.24%, 12.5%, 27.4% in A549 cells, and 7.20%, 17.5%, 31.3% inMDA-MB-231 cells, respectively. Viability in the aqueous extract groups was no different with that of controls. Conclusions: An ethanol extract of Sauromatum giganteum(Engl.) Cusimano and Hett inhibited the proliferationof SMMC-7721, SGC-7901 and MCF-7 cells, which supports the use of alcoholic but not aqueous extracts forcontrol of sensive cancers, which might include hepatocarcinoma, gastric cancer and breast cancer.