Allicin as a volatile oil content extracted from freshly garlic which is a complx includes a variety of allyl organosulfur components. One of the most biologically active ingredient of garlic. Allicin contents abundant of biological functions, lipid-lowering, anti-bacterial, alleviates inflammation, immune-enhancing, to prevent heart vascular disease and other physiological function. Compared with traditional chemical theropy, allicin is low residues in human and animals, non environmental pollution and has a broad resource. Recent study verify that allicin is able to obviously inhibite cancer cell proliferation, such as liver cancer, gastric cancer, colon carcinoma, lung cancer. Author briefly summarized recent research progress in the anti-tumor effect and mechanism of allicin.