This study carried out to changes $alpha$-amylase activity and isozymes in barley during germination in the dark and red light The specific activity of u-amylase was increased during the germination periods in the dark, giving 355.0 and 523.7 units/mg protein at 3 and 5 day, and the activity was increased by the red light up to 48 and 15% at 3 and 5 days of germination, respectively. The ratio of $alpha$-amylase I and II was approximately 95:5 at both 3 and 5 days of germination in the dark while the different ratio was found by the red light i. e. 60 : 40 and 90 : 10 at 3 and 5 days of germination, respectively.