ObjectiveTo systematically review the efficacy of immunoglobulin for treatment of clinical diagnosed viral encephalitis in China.MethodsCNKI, VIP, WanFang Data, PubMed, ScienceDirect, The Cochrane Library and EMbase databases were electronically searched to collect randomized controlled trials (RCTs) of immunoglobulin for treatment of clinical diagnosed viral encephalitis in China from inception to January 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed by using RevMan 5.4 software.ResultsA total of 57 RCTs involving 4 431 patients were included. The results of meta-analysis showed that in both children and adults of clinically diagnosed viral encephalitis, the combination of immunoglobulin could reduce the mean recovery time of fever, unconsciousness, convulsion, emesis, average hospitalization time, and non-effective rate. Moreover, there was no difference in the incidence of adverse effects between the two groups.ConclusionsCurrent evidence shows that immunoglobulin is superior to conventional therapies both in adults and children patients of clinically diagnosed viral encephalitis. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusions.