The present research was subjected to screen invitro antioxidant activity of methanolic extract of Syzygium cumini bark. Preliminary Phytochemical investigation was carried out on the methanolic extract of Syzygium cumini bark. It indices presence of Carbohydrates, Amino acids, Tannins, Saponins, Phytosterols, Terpenoids, phenols and flavones. The antioxidant activity was determined by invitro methods such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, Hydrogen peroxide scavenging assay, and Ferric reducing antioxidant power (FRAP) assay. The IC50 value of methanolic extract of Syzygium cumini for DPPH and hydrogen peroxide scavenging activity were found to be 53.3% at concentration of 600mg and 42.03% at 1.2mg/ml respectively. FRAP value found to be 810μg Fe2+/gm. The extract showed significant antioxidant activity in all antioxidant assays when compared to ascorbic acid. The results of this research work are promising thus indicating the utilisation of the bark of Syzygium cumini as a significant source of natural antioxidants.