Abstract: In recent years,various viruses bring about a serious threat to human health. It is difficult to cure various diseases caused by different virus. Active research and development of new antiviral drugs is the target of many researchers.Green tea extract is a mixture of some polyphenols whose main ingredient are several kind of catechins. Many studies have shown that these substances could fight against a variety of viruses strongly.This article is a review about the extract methods of green tea extract, its main ingredients, its anti-virus mechanisms. The summerized various theories of anti-viral mechanism lay a solid foundation for its in-depth study.