Shikimic acid is a kind of monomer compound distilled from the ripe fruit of aniseed, a kind of Chinese herb. It has the function of anti- inflammation and abirritation. It is the intermediate of anti-cancer drugs. It can obviously prevent thrombosis. It can restrain the formation of artery, vein, and cerebral thrombus. It is also the precursor of drug “Tamiflu”, which can inhibit bird flu to some extent.