Abstract: Epigallocatechin gallate ( EGCG) , the highest content of tea polyphenols, has been shown to have significant antitumor effects, but its mechanism is complex.Combined with the latest researches, this paper reviewed that the EGCG prevented the occurrence of tumors through the anti-oxidation, anti-inflammatory and other ways; the EGCG may also exhibit anti-tumors effect by inhibiting tumor suppressor gene methylation, regulation of tumor-associated protein expression, inhibition of the tumor cell growth and disturbing the tumor cell signal transduction; the mechanism of synergistic effect between EGCG and other factors on the anti-tumor effect was summarized as well, in order to provide a theoretical basis for the further study on anti-tumor effect of EGCG.