In biochemistry and medicine, antioxidants are enzymes or other organic substances, such as vitamin E or β-carotene, that are capable of counteracting the damaging effects of oxidation in animal tissues”. Because of these considerations and the wide variety seen in molecules that exhibit antioxidant ability through a multitude of mechanisms, AO activity may be interpreted in a variety of ways. Antioxidant activity of different 2-amino-5-(3-arylsydnon-4-oyl)thiazoles are studied by different methods like FRAP, -carotene assay and DPPH assay and the results are presented.