ObjectiveTo systematically review the protective effect of serum maternal respiratory syncytial virus (RSV) antibodies on infants with RSV infection. MethodsPubMed, EMbase, The Cochrane Library, CBM, CNKI and WanFang Data databases were electronically searched to collect observational studies on the correlation between serum maternal RSV antibodies and infants with RSV infection from inception to July 18, 2021. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies, then, qualitative analysis was performed. ResultsA total of 19 studies were included, and 60% of those studies suggested that a higher level of maternal antibodies could prevent RSV infection. However, the remaining 40% of them showed that there was no significant difference in the level of RSV maternal antibodies between the infected group and the non-infected group. Further more, in the studies of the correlation between maternal antibody level and disease severity after RSV infection, 55% of those showed that maternal antibody level was negatively correlated with disease severity. ConclusionThe protective effect of serum maternal RSV antibodies on infants reported in different studies varies. Whether it can prevent RSV infection and affect the severity of RSV infected children still needs to be explored.