Abstract: Bacteriocin produced by lactic acid bacteria ( LAB) is a kind of polypeptide or protein with antimicrobial activity, which can inhibit harmful bacteria for human body and can be biodegraded and digested by human body.Class Ⅱa bacteriocin produced by lactic acid bacteria is class Ⅱ bacteriocin which has N- terminal conserved sequence and can inhibit Listeria monocytogenes strongly.Owing to the stable physical and chemical properties of class Ⅱ a bacteriocins, class Ⅱ a bacteriocins have been a hot topic recently, therein, the structure- activity relationship of class Ⅱ a bacteriocin producing from lactic acid bacteria is a difficulty and challenge. For this reason, the structure- activity relationship of classⅡa bacteriocin producing from lactic acid bacteria has been widely studied in recent years. In this paper, the structure, and the structure- activity relationship of classⅡ a bacteriocin producing from lactic acid bacteria were reviewed comprehensively and systematically, and then the current main problems and future research directions were pointed out.