Cassia acutifolia, which is commonly known as Alexandrian senna is a medicinal herb belong to family of Leguminosae, The famous use of this herbal shrub is as a laxative act by stimulation intestinal muscles to contract cause the rapid removal of waste matter. Several phytoconstituents present in Senna leaves mostly contain dianthrone glycosides one of anthraquinone derivates. Two crystalline anthraquinone glucosides sennoside A & B have been reported rich in the leaves and pods, in addition to many flavonoids and terpens. this study was designed to investigate the phytochemical component and antioxidant activity of Alexandrian senna L. leaves cultivated in Iraq. this is done by extraction of plant leaves after drying using hexane then ethanol through soxhlet extractor and determine the active ingredient in the leaves extracts using standards chemical test then the antioxindant activity has been evaluated using DPPH scavenging method. The results indicate the presence of important active ingredient such as flavonoids, saponin, carbohydrate, tannin, terpenoid and alkaloids and the leaves extract show a significant anti-oxidant activity at low level with IC50 26.7 as compared with their standard ascorbic acid.