In this present study, antioxidant potential of the methanol extract of the root of Cajanus cajan Linn (MCC¬R) was identified by using 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, Reducing power assay, total antioxidant activity test and also by total Phenolic content test. In DPPH scavenging assay the IC¬50 value of the extract was found to be 17.44mig/ml while the IC¬50 value of the reference standard ascorbic acid was 15.06 mig/ml.Total antioxidant capacities of MCC¬R is expressed as the number of equivalent of ascorbic acid 266.7mg/g and the reducing power of MCC¬R increased with concentration of the sample. The amount of total Phenolic 262.31mg/g Gallic acid. These results suggest that the MCC¬R providing potent antioxidant properties and offering effective protection from free radicals. Form this view point, MCC¬R were tested for oral glucose tolerance test (OGTT) in normal mice. The postprandial blood glucose lowering effects of MCC¬R (400mg/kg) were compared to a known type 2 diabetes drug (Acarbose-50mg/kg). The MCC¬R were also tested alloxan (120 mg/kg) induced diabetic mice for 7 days.The blood glucose lowering effects MCC¬¬¬¬¬R (200mg/kg).