Plants have been the basis of traditional medicine throughout the world and continue to provide new remedies for humanity, so a great effort has been made to use available experimental techniques to identify natural antioxidants from plants. Several authors have examined the beneficial uses of these plant species. In order to contribute to the valorization of the Algerian flora, we are interested in this study by phytochemical study of two plants of Calendula officinalis and Berberis vulgaris which are much used in the traditional medicine at the region of Djelfa and evaluate their antioxidant activity with the DPPH test. The qualitative phytochemical examination of Berberis vulgaris root showed the presence of alkaloids, tannins, sterols, triterpenes and reducing compounds in large quantities, and it also revealed lower amounts of coumarins, terpenoids, saponins and mucilage. Phytochemical studies of the dried petals of calendula officinalis revealed the presence of tannins, alkaloids, Sterols and Triterpenes, and saponosides. The tests for flavonoids and coumarins were negative on our extract. The antioxidant activity of Berberis vulgaris root was measured by the DPPH free radical scavenging technique.