Lactic acid bacteria (LAB) are important industrial microor ganism used in the production and preservation of foodstuffs. Recently, considerable advances have been made in the genetics and molecular biology of LAB. These have resulted in the construction of food-grade gene expression systems for these bacteria. This paper aims to review the essential features for food-grade systems, food-grade selection markers, food-grade controlled gene expression and food-grade inducible signaling molecule, and recent developments on food-grade cloning and expression systems for LAB.These gene expression systems have great potential for studies on gene expression and regulation in LAB and a variety of bioprocessing application in industrial fermentations.