Abstract:Carbon-nitrogen lyases (E.C.4.3) are a group of enzymes that release ammonia, amidine or amino group etc,?and also show ability to form double bond or ring structure. Specifically, enzymes forming amino group are called amine-lyases (E.C.4.3.3), which are critical in the industrial production of many medicine intermediates. In this review is a summary of four major amine-lyases in terms of their source, enzymatic characteristics and their applications in preparation of pharmaceutical intermediates.