ObjectiveTo systematically review the efficacy of treatments for β-coronaviruses.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, SinoMed, CNKI and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) of treatments for β-coronaviruses from inception to June 17th, 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using Stata 14.0 software.ResultsA total of 109 studies invoving 23 210 patients were included. The results of the systematic review showed that compared with standard of care, corticosteroids could reduce mortality and increase cure rate for COVID-19. However, chloroquine could decrease cure rate. In severe acute respiratory syndrome (SARS) patients, corticosteroids could decrease the cure rate. In Middle East respiratory syndrome (MERS) patients, ribavirin/interferon/both drugs showed higher mortality.ConclusionsThe currently limited evidence shows that corticosteroids may be effective to COVID-19 patients while having limited effects on SARS patients. Hydroxychloroquine or chloroquine may have negative effects on COVID-19 patients. Ribavirin/interferon may be harmful to MERS patients. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusions.