Abstract: The lactate dehydrogenase was a key enzyme which converts pyruvic acid to lactic acid in lactic acid bacteria. In this paper,the research progresses of the classification,structures and functions of the lactate dehydrogenases,as well as the microbial genuses and synthetic metabolic pathway of the lactic acid production were summarized. This review will assist in understanding the metabolic regulation of lactic acid synthesis in many different species and genera,hoping for theoretical guidance for others.