Abstract: Gamma-aminobutyric acid (GABA) is a four carbon, non-protein amino acid which is widely distributed in nature. Due to its important physiological activities, GABA has been widely used in the food, medical and chemical industries. Based on 83 references, the research progresses of microbial biosynthesis pathway of GABA and glutamate decarboxylase are reviewed, the species and sources of GABA producing microorganisms are summarized, and the factors affecting GABA production are discussed, and future research focus in this field are prospected.