Background: Both alcohol and aqueous extracts of Sauromatum giganteum(Engl.) Cusimano and Hett, the dried root tuber of which is named Baifuzi in Chinese, have been used for folklore treatment of cancer in Northeast of 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 of Sauromatum giganteum(Engl.) Cusimano and Hett, prepared by heat reflux methods, on proliferation of different cancer cells. Results: Cancer cells treated with medium supplemented with 10%, 20%, 40% serum(v/v) containing ethanol 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 HepG2 cells, 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% in MDA-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 proliferation of SMMC-7721, SGC-7901 and MCF-7 cells, which supports the use of alcoholic but not aqueous extracts for control of sensive cancers, which might include hepatocarcinoma, gastric cancer and breast cancer.