Abstract: Seed ageing is a main problem of seed storage. Unsuitable storage conditions with high moisture and temperature increases seed ageing. Ageing induces seed deterioration expressed as the loss of seed vigour and/or viability. An experiment was conducted in order to investigate the activity of catalase and peroxidase during accelerated ageing and repair during priming treatment of maize (Zea maize L.) seeds. In order to improve germination characteristics in aged seeds seed priming with KNO3 was performed at different concentration of (0.5, 1, 2.5 and 4%) and seeds were soaked for 8, 12 and 24 h in each individual concentration. Results of study showed that there is significant difference for duration of ageing treatment on germination characteristics of maize seeds. Increasing ageing duration resulted higher reduction in germination characteristics. KNO3 had positive effects on seed germination of aged seed. This was higher in application of 0.5% KNO3 for 8 h and 2.5% for 24 h. Antioxidant activity of aged seeds increased after seed priming treatments. Hormone seed priming is more effective than seed priming with KNO3 in activation of antioxidant enzymes. It is suggested that using seed enhancement treatments like seed priming could improve aged and non-aged seed performance especially for high aged seeds.