Glinus oppositifolius and Trianthema decandra belonging to the Ficoidaceae family were commonlyused by tribal peoples for the treatment of liver disorders and cancer. The preliminaryphytochemical screening of those plants showed the presence of flavonoids, terpenoids, tanninsand saponins. The aim of this study was to evaluate the in vitro antioxidant activities of the methanolextracts of Glinus oppositifolius (MEGO) and Trianthema decandra (METD). The antioxidative capacities ofMEGO and METD were determined by the following four complementary assay; DPPH radicalscavenging assay, superoxide anion generation by xanthine-xanthine Oxidase assay, hydroxylradical scavenging assay and Fe2+–ascorbate induced by lipid peroxidation assay. The IC50 values ofthe both extracts were calculated from the inhibition curve. The IC50 MEGO and METD in DPPH,superoxide anion, hydroxyl radical scavenging and lipid peroxidation assay are 1.85, 7.31, 13.95, 22.82and 2.21, 9.78, 14.87, 19.76 µg/ml respectively. Both the extracts exhibited a significant antioxidanteffects.