Effects of fermentation time,temperature,initial p H,buffer system,pyridoxal phosphate and VB6onγ-aminobutyric acid accumulation in fermented defatted wheat germ using Lactobacillus plantarum DY-1 were investigated. Gama-aminobutyric acid content in fermented wheat germ was determined by paper chromatography. On the basis of single factor,the fermentation conditions of γ-aminobutyric acid accumulation were optimized by orthogonal experiment. The results showed that fermentation time had a significant influence on the γ-aminobutyric acid accumulation. The optimal conditions for γ-aminobutyric acid accumulation were identified as fermentation time of 24 h,initial p H of 5. 0 and VB6 concentration of 0. 2 mmol / L. The concentration of γ-aminobutyric acid under optimal conditions was determined as 0. 954 mg / m L using paper chromatography. The accrue concentration of γ-aminobutyric acid was determined as 0. 402 mg / m L using amino acids analysis. By lactic acid fermentation,γ-aminobutyric acid in wheat germ increased by 3. 4 times.