Oxidative stress is a probable cause of multi organ failure in this setting which never has been evaluated in COVID-19 infection to the best of knowledge.Present study aimed to evaluate oxidative stress marker and redox system status in different COVID-19 patients regarding the severity of involvement. Demographic and lab data of 60 COVID-19 confirmed positive cases gathered .These patients divided in to two arms: 1- severe COVID-19 which were intubated or admitted in intensive care unit due to severe hypoxia 2- non-severe COVID-19 patients which were not hypoxic and admitted in ward with no need to invasive oxygenation. All patients had positive RT-PCR positive nasopharyngeal swab results for COVID-19 or Lung CT scan compatible with COVID-19. Malondialdehyde(MDA) , Biopterin, Neopterin, SOD, Glutathione levels would be checked by ELISA tests and compared between these two groups and healthy controls.