The aim of this study was to determine the effects of Abscisic acid, CaCl2 and acclimation (15°C) pre-treatments on the activities of antioxidant enzyme system under cold stress (5°C) in maize seedlings in the dark. When corn seedlings were imposed to cold stress for 7 day at 5°C in the dark, antioxidant enzyme system was induced and protected the seedlings. At first, malondialdehyde (MDA) levels as a product of lipid peroxidation were measured. ABA at 0.1 ρM and CaCl2 at 0.75 mMdecreased MDA levels in roots and shoots significantly, indicating that antioxidant enzymes are activated and cold injury is reduced. Measuring the relative activities of SOD, APX, CAT, GR and GPX revealed that, ABA and CaCl2 promoted their activities in roots and shoots significantly. The enhancing effects of ABA on the activities of all enzymes under cold stress were higher than CaCl2 and 15°C acclimation temperature. Calcium treatments were second in this respect. The role of ABA and Ca2+ was discussed in this study.