10.22376/ijpbs.2019.10.1.p1-12 Volume 4 Issue 3 2013 (July - September) In order to identify new sources of safe and inexpensive antioxidants, the antioxidant capacity and total phenolic content of 5 microalgae isolated from fresh water lakes of Kumaun Himalayan Region were evaluated, using DPPH-Radical scavenging activity assay and the Folin-Ciocalteu method, respectively. The microalgae were extracted using methanol by a three step sequential extraction procedure. Most of these microalgae were evaluated for the first time for their antioxidant activities. It was found that microalgae lessThan i greaterThan Chlorella vulgaris lessThan /i greaterThan and lessThan i greaterThan Mougetia parvula lessThan /i greaterThan possessed the higher antioxidant activities and thus could be a potential rich source of natural antioxidants. In addition, the correlation coefficients between the antioxidant capacities and the phenolic content were very high ( lessThan i greaterThan R lessThan sup greaterThan 2 lessThan /sup greaterThan lessThan /i greaterThan = 0.9882). It is clear from the present investigation that phenolic compounds played key role in regulating antioxidant capacities of these microalgae. SHWETA NAILWAL AND TAPAN KUMAR NAILWAL Antioxidant capacities, Microalgae, Kumaun Himalayan Region, Phenolic content 349-355