The present study was aimed to study enzymatic antioxidants (superoxide dismutase, catalase, polyphenol oxidase), nonenzymatic antioxidants (saponin, flavonoids, ascorbic acid and tannin), and anti-oxidant ability assays (total anti-oxidant, hydroxyl radical scavenging ability, reducing power activity, inhibition of lipid peroxide formation, DPPH scavenging activity and metal chelating assay) in I. marginata leaves and whole plant. The results revealed that I. marginata possessed significant enzymatic anti-oxidants activities like superoxide dismutase, catalase, polyphenol oxidase in whole plant of I. marginata. The non-enzyme anti-oxidants namely saponin, flavonoids, ascorbic acid and tannin showed maximum activity in leaves while the total phenol in whole plant. The anti-oxidant ability assays such as reducing power activity, DPPH scavenging activity and metal chelating assay were found to be high in whole plant. From the study, it was confirmed that the whole plant of I. marginata showed strong antioxidant ability assay. Thus I. marginata whole plant can be used as a potential source of natural anti-oxidants.