Abstract: Different plant seeds extracts of Citrus sinensis, Hordeum sativum, Triticum sativum, Canna indica, Citrullus vulgaris and Capsicum annuum were evaluated for their antioxidant activity by the following methods: 2,2-diphenyl-1-pycril-hydrazyl (DPPH) radical scavenging, reducing power, RBCs hemolysis and linoleic acid oxidation, a long with the determination of total phenolic and flavonoids contents. All the methanolic extracts showed high antioxidant activity and have high contents of phenolic and flavonoid. The Canna indica extract exhibited strong antioxidant as a reducing power and as DPPH radical-scavenging (3.61 absorbance, 87.12%, respectively), while the Hordeum sativum extract exhibited highest inhibitory effect on RBCs hemolysis (59.55%) and the Capsicum annuum extract has highest inhibitory effect on linoleic acid peroxidation (65.06%).