Abstract: ObjectiveEffects of gamma-aminobutyric acid(GABA) on photosynthetic activity and antioxidant activity were studied under salt stress,in order to reveal the machanism of GABA in improving salt resistance of wheat.MethodGrowth parameters,such as gas exchange,actual quantum yield of photosynthesis,photosynthetic pigments, activities of antioxidant enzymes,malondialdehyde(MDA) contents and relative electrolyte leakage(REC) in wheat seedlings were determined under different GABA concentrations. And effects of different treatments on photosynthetic activity and antioxidant activity of wheat were compared.ResultExogenous GABA can increased photosynthetic activity and antioxidant activity of wheat seedlings. Treated by 0.75 mmol/L GABA,photosynthetic activity and antioxidant activity of wheat significantly increased(P<0.05),and the damaged biological membrane was repaired.ConclusionGABA improves the resistance of wheat to salt by increasing photosynthetic activity and antioxidant activity of wheat.