Abstract:Trehalose is a naturally occurring non-reducing disaccharide. This sugar has been known as a protector of biomembrane and macromolecules. And it has been widely used in foods, medicines, cosmetics. Trehalose synthase (TreS) is an intramolecular transglycosylase. It can catalyze the conversion of maltose into trehalose in one step. As the simple protocol and cheap substrate, it is very prospect in the industrial production. Here we have discussed the properties, catalytic mechanism and gene-engineering of TreS, and also proposed some solutions to its present research problems.