Glutamine is the most abundant amino acid in the blood and has the ability to help preserve the intracellular pool of free amino acids in the body,which is a regulator of protein synthesis and correlates with nitrogen balance.Being the original strain,Corynebacterium glutamicum A-26 was mutagenized by NTG and the UV-radiation,then a mutant resistant to sulfaguanidine(SG),methionine sulfoxide(MSO) and(NH4) 2SO4 was obtained.It was named Corynebacterium glutamicu N-U-6.1.14 times glutamine(33.54 g/L) more than the original strain(15.64 g/L) was produced by the mutant.Its good hereditary stability was also tested.