【Abstract】 This paper reviewed the research progress of producing 2 keto L gulonic acid, an important precursor of L\|ascorbic acid, from D\|Glucose by constructing recombinant microorganisms.At first, the background of producing 2\|KLG from D\|glucose by tandem\|fermentation and one step fermentation through gene engineering techniques is introduced. Then, how to optimize the expression of 2,5\|DKG reductase and block the side\|pathways by creating mutants in the 2\|keto aldose reductase genes in vitro and in vivo by allelic replacement is focused. At the same time, the protein engineering of 2,5\|DKG reductase is also mentioned. Finally, the future of this research and possibility of application are discussed.\;更多还原