The antioxidant activity of barley spent gains was investigated with different methods .The reductive ability and the scavenging of hydroxy free radical ,superoxide anion free radical ,DPPH free radical of barley spent gains polyphenols were used to evaluate the antioxidant activity .Results demonstrated that polyphenol from barley spent grains showed high scaven‐ging activity of hydroxyl radical ,superoxide anion radical and DPPH radical ,the concentrations for 50% inhibition of essence extract were 4 .132 ,89 .504 ,15 .304μg/ml ,respectivel...