The present study was carried out to determine the concentration of some bioactive phytochemicals (ascorbic acid, carotenoids, total phenolics, protein and carbohydrate) and their antioxidant activity in the some medicinal plants. To screen out the plants, as well as their parts having higher antioxidant activities, all main parts of plants were screened. Out of thirteen plant samples, ethanolic leaf extract of T. belerica showed minimum IC50 for free radical scavenging capacity (0.08 mg/ml), superoxide anion radical scavenging activity (0.39 mg/ml), lipid peroxidation (0.31 mg/ml) and ferric thiocyanate chelation activity (0.89 mg/ml) as well as high reducing power (0.31 ASE/ml) capacity. We can infer that the parts of plant having high content of phytochemicals may serve as a good source of nutraceuticals which have potential for use in health care formulations.