L-Ergothioneine (L-EGT) is a sort of uncommon thimidazole amino acid with strong antioxidant activity,which cannot be degrated at high temperature and pH.L-EGT only can synthesized by some bacteria,cynobacteria and fungi,but plants,animal and human unable to synthesized.Mammals absorb L-EGT via transporter OCTN1 which distribution in different tissues,thus diverse tissues may influence concentration of L-EGT.With the unique physiological and pharmacological activities made it have extensive application prospect in the field of medicine,food,health care products and cosmetics.Here,we reviewed the recent advances in biosynthetic pathway of L-EGT,and in-depth exploration its roles in food,human health and diseases.