With a synonym of iron fan, mulberry leaf belongs to moraceae. In recent years, researchers of different countries have conducted a systematic study on the composition, function and functioning mechanization. As a result, they found that there are a great deal of nutrition component and biological active substance in it and it has such functions as reducing blood sugar, blood pressure, blood fat and postponing decrepit. Especially, the DNJ substance within it is a functioning substance that other plants and animals don't have. Eat together with food, it has functions as constraining the rise of blood sugar and preventing diabetes. In addition, Mulbcrrin within mulberry leaf has cancer resistant activity and the function of constraining epiphyte. Experiment shows, N-Me-DNJ, GAL-DNJ, fagomine can reduce blood sugar level significantly, of which, GAL-DNJ, fagomine has the most obvious sugar reduction roles. Mulberry leaf is tasty, it has rich calcium and iron and nutrition contents. With no side-effects, it is a kind of new generation natural functional health raw material. Mulberry leaf series products will be fashionable product in the current world catering structure.