Estimates have suggested that up to 12% of patients hospitalized with COVID-19 have required invasive mechanical ventilation, with the majority developing acute respiratory distress syndrome(ARDS). Corticosteroids are the most potent antiinflammatory drugs. The therapeutic mechanism of corticosteroids might base on attenuating the action of many cytokines that participated in the inflammatory reaction associating severe CAP However, the clinical and efficacy of dexamethasone in COVID-19 patients are currently unclear, so research is needed to know the effectiveness of dexamethasone therapy in patients with COVID-19. This research uses a structured analysis focused on preferred reporting items for systematic reviews and meta-analyzes (PRISMA) in order to classify all existing literature with appropriate keywords. The database using PRISMA (Preferred Reporting Items for Systematic Reviews & Meta Analyses) for instruments and used flowcharts based on the 2009 PRISMA checklist and based on inclusion and exclusion criteria, we found that dexamethasone resulted in a significant increase in the number of ventilator-free days (days alive and free of mechanical ventilation) over 28 days in patients with COVID-19 and moderate or severe ARDS.