Introduction: Selena-diazole has antioxidant, and antitumor activities. Also selena-diazol exhibited promising antifungal, antibacterial, viral infection and neurodegenerative disease. The aim of the study is to evaluate the antioxidant activity of a novel -(4,5,6,7-tetrahydro- [1,2,3-] selenadiazolo [4,5 e] pyridine-4,6-diyl) bis(benzene-1,3-diol) (T) against dipyrone (Di) induced oxidative stress. Methods: In vitro antioxidant using DPPH, concentrations of T and ascorbic acid (AA) at 10, 20, 30, 40 and 50μg was measured. In vivo study conducted using four groups, received 50mg/kg of T or/and Di and DW for 30 days. Antioxidant estimated in vivo by serum superoxide dismutase activity (SOD); Glutathione Peroxidase enzyme GPx measured by using Rat SOD1 kit and Rat GPX1 ELISA Kit respectively. Furthermore, Malondialdehyde (MDA) is reliable biomarkers to predict oxidative stress. Results: The results indicate IC50 rate using DPPH of T compound 48.888μg/ml. GPx of T and T&Di groups were significantly increased. SOD of T was significantly increased than other groups. MDA results presented essential reduction in T group value than Di group. Conclusion: The study concluded that synthesized novel selena-diazole derivative T has a good effect as an anti-oxidant.