The effects of growing seasons on the enzymatic activities (alpha-amylase and dehydrogenase) of seeds of five sesamum genotypes viz., Uma, Amrit, Nirmal, CUMS-17, and Prachi in six developmental stages (7,14, 21, 28, 35 and 42 DAA) were investigated. The experiment was conducted in the Department of Seed Science and Technology, OUAT, Bhubaneswar during 2014-16. The alpha-amylase and dehydrogenase activities in the developing seeds increased consistently till 35 DAA after which there was slight decrease in values of these traits up to maturity (42 DAA). Among the varieties, Prachi registered the highest alpha-amylase activity (140.25µg/g) followed by CUMS-17 (137.00µg/g) at physiological maturity stage (35 DAA) and Uma had the lowest value (124.25µg/g). Among the growing seasons, the kharif seeds had the highest alpha-amylase activity (140.75µg/g) followed by summer (131.50 µg/g) and rabi (122.65µg/g). Among the sesame varieties studied, the dehydrogenase activity was found to be highest in Prachi and CUMS-17 (0.36 mg/g and 0.33 mg/g) and lowest in Uma (0.28 mg/g). The khaif harvest seeds registered the highest dehydrogenase activity (0.34 mg/g) followed by summer (0.30 mg/g) and rabi (0.29 mg/g) followed by those produced in summer (0.06mg/g) and rabi (0.05mg/g).