In the present study, olive leaves of eight varieties were investigated for the total phenol and flavonoid content, for the major compound and for the in vitro antioxidant properties. The different varieties showed a high content of polyphenol and flavonoid. Oleuropein was the major compound of the leaf extract for all varieties. Also, olive leaves extract exhibited a good antioxidant activity and a reduced power, each variety showed its own feature. A significant negative correlation between anti-radical activities and oleuropein content was observed only for four varieties (r=-0.94). The high oleuropein content and the important antioxidant activities of olive leaves extract could be useful sources for industrial extraction and pharmacological application in the promotion of health and prevention of damages caused by radicals.