THE CURRENT study was conducted during season 2013 on …… one-year-old mango seedlings of Golek, Misk, Hindi Besinnara, Sukkary and Zebda cvs. to investigate the activities of both enzymatic and non-enzymatic components of the antioxidant system in mango under salinity stress. Plants were subjected to three levels of salinity (0, 1000 and 2000 mg L-1). The activities of peroxidase, (POD), catalase, (CAT), polyphenyl oxidase (PPO), membrane stability index were determined and leaf content of reduced glutathione, chlorophyll, ascorbate and total sugars were determined. Activities of antioxidant enzymes, membrane stability index, ascorbate and reduced glutathione contents were significantly altered by salinity treatments. Leaves of salt-stressed plant exhibited a greater activity of peroxidase and polyphenyl oxidase while reduced activity of catalase. Reduced glutathione and membrane stability index increased by increasing salinity level. Salinity effect was less evident on chlorophyll and total sugar content. The differences between the studied cultivars were evident in most of the studied parameters. Zebda cultivar showed a higher antioxidant potential which provide a resistance mechanism agent salinity stress.