In this study, Antioxidantl activity of flavonoids from plants.(Artemisia herba-alba, Ruta chalpensis L., Rhamnus alaternus L.) Flavonoids is a substance found naturally in many plants which benefits health both prevention and treatment, and plays a role in antioxidant activity. it enhances the immune system, prevents heart disease. Flavonoids compounds dissolve in water. The excess is excreted from the body in urine, therefore, no poison and side effects of any kind. Free radicals are atoms or molecules with unpaired electrons. Many diseases are caused by free radicals, for instance, aging, cancer, coronary heart disease, arthritis, allergies and high blood pressure. Normally free radical formation is controlled naturally by various beneficial compounds known as antioxidants. The quantitative method used for antioxidants determination is Diphenyl-Picryhydrazyl (DPPH) radical scavenging assay. The results showed that all extract from plants tested features antioxidant and flavoniods substance demonstrates remarkable potential as a valuable source of antioxidant.