Six γ-aminobutyric acid(GABA)-producing lactic acid bacteria(LAB) strains were screened from different kimchi samples.The strain A showed the highest GABA-producing ability of 1.261 g/L.Strain A was named as Lactobacillus plantarum WZ011 via 16S rDNA analysis.Fermentation medium was optimized using single factor test and orthogonal design methods.The optimal medium composition was glucose 13,yeast 5,monosodium glutamate 12,C8H11NO3·HCl 0.15,CH3COONa2,MgSO4·7H2O 0.02,MnSO4·4H2O 0.001,FeSO4·7H2O 0.001,NaCl 0.001,and water 1 000 mL.It was concluded from the curve of the fermentation kinetics that GABA fermentation process included two stages of cell growth and product formation.When nitrogen source was decreased and C8H11NO3·HCl was added,the utilization rate of monosodium glutamate rose to 99% and GABA production rate were increased more than twice.Under the optimum conditions,the highest GABA production reached 5.814 g/L,which was 79% higher than that of original fermentation condition.Furthermore,the duration of reaching the sationary phase of GABA production was decreased for 48h compared to the original fermentation conditions.